DNA World

Chromosome In Situ Hybridization

2011-07-01T04:13:00.001-07:00

A modern approach to the specific location of genes on chromosomes is a technique for the hybridization of DNA and RNA "in situ." With this procedure, specific radioactive RNA or DNA (known as probes) can be isolated (or synthesized "in vitro") and then annealed to chromosomes which have been treated in such a manner that their basic double stranded DNA has been "melted" or dissociated.

In theory, and fortunately in practice, when the DNA is allowed to re-anneal, the probe competes for the binding, but only where it mirrors a complimentary sequence. Thus, RNA will attach to the location on the chromosome where the code for its production is to be found. DNA will anneal to either RNA which is still attached to a chromosome, or to the complimentary sequence DNA strand within the chromosome. Since the probe is radioactive, it can be localized via autoradiographic techniques.

Finally, it is possible to produce an RNA probe that is synthesized directly from repetitive sequences of DNA, such as that found within the nucleolar organizer region of the genome. This RNA is known as cRNA (for copied RNA) and is a convenient source of a probe for localizing the nucleolar organizer gene within the nucleus, or on a specific chromosome.

The use of in situ hybridization begins with good cytological preparations of the cells to be studied, and the preparation of pure radioactive probes for the analysis. The details depend upon whether the hybridization is between DNA (probe) and DNA (chromosome), DNA (probe) and RNA (chromosome), or between RNA (probe) and DNA (chromosome).

Preparation of the Probe:

Produce radioactive RNA by incubating the cells to be measured in the presence of H-uracil, a specific precursor to RNA. Subsequent to this incubation, extract rRNA from the sample and purify through differential centrifugation, column chromatography or electrophoresis. Dissolve the radioactive RNA probe in 4X Saline-Citrate containing 50% formamide to yield a sample that has 50,000 to 100,000 counts per minute, per 30 microliter sample, as determined with a scintillation counter. Add the formamide is added to prevent the aggregation of RNA.

Preparation of the Slides:

Fix the materials to be studied in either 95% ethanol or in 3:1 methanol:water, attach to pre-subbed slides (as squashes for chromosomes) and air dry.

Hybridization

Place the air dried slides into a moist chamber, usually a disposable petri dish containing filter paper and carefully place 30 microliters of RNA probe in 4X SSC-50% formamide onto the sample.

Carefully add a cover slip (as in the preparation of a wet mount), place the top on the container and place in an incubator at 37° C for 6-12 hours.

Washing:

Pick up the slides and dip into 2X SSC so that the coverglass falls off.

Place the slides in a coplin jar containing 2X SSC for 15 minutes at room temperature.

Transfer the slides to a treatment with RNase (50 microgram/ml RNase A, 100 units/ml RNase T1 in 2X SSC) at 37° C for 1 hour.

Wash twice in 2X SSC, 15 minutes each.

Wash twice in 70% ethanol, twice in 95% ethanol and air dry.

Autoradiography:

Add photographic emulsions to the slides and after a suitable exposure period, develop the slides, counterstain and add cover slips.

Analyze the slides by determining the location of the radioactive probe on the chromosomes or within the nuclei.

(Dr. William H. Heidcamp)

DNA Nanoparticles Protocols

2011-07-01T04:12:00.000-07:00

Bioresponsive Targeted Charge Neutral Lipid Vesicles for Systemic Gene Delivery

Weijun Li and Francis C. Szoka, Jr.1

Department of Biopharmaceutical Sciences and Pharmaceutical Chemistry, School of Pharmacy, University of California at San Francisco, California 94143-0446, USA

1Corresponding author (szoka@cgl.ucsf.edu)

INTRODUCTION

This protocol describes a stepwise procedure to prepare nucleic acids encapsulated in a polyethylene glycol (PEG)-shielded nanolipoparticle (NLP) that contain a bioresponsive lipid and ligand. This process provides several advantages for systemic gene delivery. The in vivo circulation time is extended. Also, low pH-sensitive lipids enhance DNA unpacking and endosomal escape. Finally, ligands inserted into the NLP surface can target gene delivery to specific tissues or cells in vivo.

Lipoplex and LPD Nanoparticles for In Vivo Gene Delivery

Li Shyh-Dar1, Li Song2, and Huang Leaf1,3

1 Division of Molecular Pharmaceutics, School of Pharmacy, University of North Carolina at Chapel Hill, North Carolina 27599, USA
2 Center for Pharmacogenetics, School of Pharmacy, University of Pittsburgh, Pennsylvania 15213, USA

3Corresponding author (leafh@pitt.edu)

INTRODUCTION

Lipoplex (cationic liposome-DNA complex) is formed via electrostatic interaction of anionic nucleic acids with cationic liposomes. A thin film of lipids is dried on the bottom of a glass tube and rehydrated in an aqueous solution. The resulting liposome suspension is passed through polycarbonate filters of desired pore size. This protocol also describes the preparation, physical properties, and biological activity of liposome-polycation-DNA (LPD) nanoparticles. The LPD nanoparticles contain a highly condensed DNA core surrounded by lipid bilayers with an average size of ~100 nm. The nanoparticle complex is injected into mice, and expression of the transfected DNA is monitored with an appropriate assay.

PEI Nanoparticles for Targeted Gene Delivery

Frank Alexis, Jieming Zeng, and Wang Shu1,2

Institute of Bioengineering and Nanotechnology, Singapore 138669
1Department of Biological Sciences, National University of Singapore, Singapore 117543

2Corresponding author (swang@ibn.a-star.edu.sg)

INTRODUCTION

This protocol describes the preparation of polyethylenimine (PEI)/DNA nanoparticles for targeted gene delivery. This delivery strategy improves the efficiency of gene transfer by enhancing the entry of gene vectors into the desired cells and reducing uptake by nontarget cells. We describe here methods for theconjugation of targeting peptides to PEIs, formation of DNA complexes using the conjugated PEIs or nonconjugated PEIs together with targeting peptides, and cell transfection using these complexes. The conjugation step involves the use of the succinimidyl-4-(N-maleimidomethyl)cyclohexane-1-carboxylate(SMCC), a heterobifunctional cross-linker, to form a stable bond between PEI and peptides containing thiol groups.

Preparation of Gold Nanoparticle–DNA Conjugates

T. Andrew Taton1
1University of Minnesota, Minneapolis, Minnesota

Publication Name:

Current Protocols in Nucleic Acid Chemistry

Unit Number: UNIT 12.2

DOI: 10.1002/0471142700.nc1202s09

Online Posting Date: August, 2002

ABSTRACT

This unit describes the preparation of conjugates between nanometer-scale gold particles and synthetic oligonucleotides. Oligonucleotide-functionalized gold nanoparticles are finding increased use in both the construction of complex, tailored nanostructures and the optimization of DNA sequence analysis. The protocols in this unit outline the synthesis, purification, and characterization of nanoparticle-DNA conjugates for applications in nanotechnology and biotechnology. Separate procedures are presented for nanoparticles functionalized with just one or a few oligonucleotide strands and for nanoparticles functionalized with a dense layer of oligonucleotide strands. The different physical and chemical properties of these two types of conjugates are discussed, as are their stability and utility in different environments.

Chitosan-plasmid DNA nanoparticles used for contraceptive vaccine.

Publication: Immunotherapy Weekly

Publish date: July 21, 2004

2004 JUL 21 - (NewsRx.com & NewsRx.net) -- Researchers have prepared chitosan-plasmid DNA nanoparticles encoding zona pellucida glycoprotein-3 alpha and characterized its expression in the mouse.

"In the present study, the porcine zona pellucida (ZP)-3alpha eukaryotic expression vector pVAX1-pZP3alpha was constructed by genetic recombinant technology, then the recombinant plasmid was encapsulated in nanoparticles with chitosan, and the imaging of chitosan/pVAX1-pZP3alpha nanoparticles by Atomic Force Microscope (AFM) was processed. Feeding mouse with those microencapsulation by gastric larvae, and after five days, detecting its expression in mouse intestine by RT-PCR …

DNA and Evidence Collection Principles

2011-07-01T04:11:00.000-07:00

Robert E. Kramer

The dawn of a new age has arrived in law enforcement in the form of DNA research and testing. We in law enforcement, especially those of us working the crime scenes need to be aware of what we can do "in the field" to assure that proper evidence collection techniques are followed. Only then will the groundwork for successful evidence examinations be in place when we submit the case to a forensic laboratory for analysis.

Polymerase Chain Reaction

Polymerase Chain Reaction (PCR) is the DNA evidence analysis technique which is being practiced at the state laboratory at the Division of Criminal Investigation in Des Moines. PCR is a sensitive, fast, and highly discriminatory method of analysis. One of the most essential aspects of DNA evidence analysis at the lab is that a basis knowledge of evidence collection principles is necessary at the initial stage. PCR allows the criminalist to examine evidence which has been properly collected and preserved with expectations that accurate results will be found as result of the analysis.

Impact and Exchange

It is widely embraced within the law enforcement forensic field that, to at least some degree, the process of impact and exchange occurs at every crime scene. For example, a "run" vehicle impacts the accident scene and exchange occurs with the transfer of paint to the victim vehicle; a burglar impacts a scene with the approach of the area, and exchange occurs when footwear impressions are left behind. As law enforcement officers and crime scene specialists, it is our job to collect and preserve evidence at the scene - evidence which may not only connect the suspect to the scene - but connect the suspect to the incident itself.

Swab Method

The collection and preservation of evidence which will be subjected to DNA analysis is best accomplished by the seizure and submission of the original item. For example, it would be desirable to collect and submit undergarments worn after an incident involving suspected sexual assault rather than cutting or swabbing the specimen. Sometimes, however, the submission of the original item is impossible or impractical. Imagine a shooting or stabbing scene where there is evidence of considerable blood loss on a tile or linoleum floor. The practice of swabbing for the evidence is then practical for collection of possible DNA evidence.

It is preferred that swabs to be submitted to the D.C.I. Lab in Des Moines be made with cotton tipped swabs (ie: Q-tiptm). The process is simple, and the following outlines the procedure:

Slightly moisten a cotton tip swab with clean water.

concenrate the stain as much as possible.

avoid potential sample-to-sample contamination during the process.

avoid contamination by the collector (wear protective clothing).

if cotton balls are chosen as the collection medium, forceps used (if applicable) need to be cleaned thoroughly after each specimen.

(2) Air dry - NEVER use a hair drier.
(3) Package separately in paper (no plastic containers).
(4) Keep out of direct sunlight.

Eliminating the chances of cross, sample-to-sample, or collector contamination cannot be stressed enough. There are steps which can be taken in advance which will both: a) make the job easier, and b) reduce and possible eliminate that chance of evidence contamination.

Preparation is the key word when it comes to DNA evidence collection. You wouldn't wait until the night of a multi-thousand dollar safe burglary to order footwear casting and fingerprint supplies from the manufacturer would you? Some very low cost supplies can be obtained in advance which will "keep" for a considerable period of time. Paper, plastic, or wooden shafted swabs all work fine, but the durability of the wooden shaft swabs should be considered. A styrofoam block should be obtained and kept in your evidence collection kit. The wooden shaft swabs can be placed, shaft end down, in the block and allowed to dry. Prior to doing so, you may want to affix a piece of double side sticky tape on the bottom of the block to prevent it from tipping over as the swabs are attached to it. Small adhesive labels can be purchased and attached to the swab (prior to the sample being collected) which can be used to identify the swab. When the swabs are dry they should be placed in separate paper envelopes for preservation. Plain letter envelopes work well, although manilla or glycine envelopes are equally suitable.

The cotton swabs, a small glass jar (with a secure lid) of water, latex gloves, envelopes, stickers, a marker, and the styrofoam can be packaged neatly in a tackle box. (I prefer a $1.49 plastic pencil case purchased at the local discount department store). NOTE: In the interest of really saving time at the crime scene, package the swabs in individual envelopes in advance. This reduces handling the swab at the scene - and if using manilla envelopes, place the swab tip-side-down so that it may be removed from the envelope without handling the cotton end.

Tape Lift

Dried blood samples can be conveniently lifted from non-porous surfaces with conventional fingerprint tape. This process is beneficial in that the very size and shape of the stain may in fact be preserved on the lift. Of course, the lift should be placed sticky side down on a piece of plain white typing paper. It is suggested that paper be used (in lieu of plastic or fingerprint backing material) due to the fact that the paper will allow the specimen to "breath" As with the swab, the lift should be packaged in a separate envelope.

Control Samples

When conducting DNA analysis, the criminalist needs to have a "control" sample to compare with the suspect swab/evidence. For this reason, the crime scene examiner needs to document, collect, and preserve a control sample with the same care that the suspect sample is treated. For obvious reasons, it is suggested that the control sample be collected prior to the suspect sample. By collecting the control sample first, there is less chance of contaminating it with the blood or other biological fluid as the subsequent samples are being collected. Also make sure the same water is used to collect both the control and evidence samples. Finally, if cuttings of a suspected sample are being submitted for analysis (ie: a couch) it is preferred that the control samples also be cuttings, rather than swabs or merely fibers.

Other Evidence

Known biological specimens can be collected from both living and deceased persons easily, and we have been doing so for years in the form of sexual assault kit supplies. Known blood in quantity should be collected and preserved in one of the three following tubes:

Grey NaF (blood alcohol)

Purple (EDTA)

Yellow (ACD) sexual assault kit

Red top (plain) or green top (heparin) tubes SHOULD NOT BE USED.

Cheek swabs can be collected from individual and may in fact result in the discovery of some of the most highly concentrated DNA cells. The cheeks swab is non-threatening, in that the individual feels less intimidated by the process. The procedure is quick and simple:

A cotton tipped swab is scrubbed on the inside of the cheek.

No food or drink prior to twenty minutes of the collection.

Preferred that the technique no be used if the mouth is bleeding.

Deceased Individuals

Common sense and knowledge of previously approved practices seem to be the rule when deceased individuals are concerned, particularly when severe decomposition is present and blood work not practical. If hairs are to be submitted, make sure the collector obtain pulled hairs. The tissue associated with the hair root is needed in the DNA analysis. Other samples which may be suitable for DNA analysis include: bones (rib or long bones preferred), teeth, muscle tissue, and associated property which may be found with the body (hairbrush, toothbrush, etc.)

Questioned Evidence

The following are being submitted as miscellaneous tips which should be considered prior to and during the DNA evidence collection process....

positive considerations

saliva: cigarette butts, ski masks, envelopes, stamps.

seminal fluid: oral, rectal, vaginal swabs, clothing.

blood: (if the stain is visible - DNA results are likely)

hair

negative considerations

urine and feces.

biological samples contaminated with soil.

some substrates (jeans - denim) have proven to compromise DNA analysis.

Wear protective outer clothing, as well as the standard latex gloves. Since the crime scene examiner is subjected to exposure to elements, it is recommended that the outer clothing be changed upon returning to the scene after leaving.

Finally - maintain the samples at ambient conditions or cooler. Room temperature is acceptable, refrigeration is desirable, and freezing is preferred.

REMEMBER - practice common sense. Don't let the collection of biological evidence be intimidating. If sound procedures are followed, successful and thorough crime scene work can be accomplished in a safe manner, with valuable evidence in hand.

Hop DNA Extraction Protocol

2011-07-01T04:10:00.000-07:00

1. Obtain an adequate amount (~ 1g) of fresh hop leaves and crush them with liquid Nitrogen and a small amount of Carborundum powder (fine 320 grit).

2. Assume 90% of mass is water weight.

3. Add 3.3 ml of buffer per gram of wet (16 ml per gram of dried) hop leaves, and incubate for 1 to 4 hours at 60-65°C.

4. Transfer 900 μl into fresh tube

5. add 600 μl of 24:1 CHCl3:octanol and invert gently (do NOT vortex!).

6. Centrifuge at 5000g for 10 minutes.

7. Transfer supernatant (800 μl) into new 2-ml tube.

8. Add 5μl of RNAase and incubate at 37°C for 30 minutes (or more).

9. Add 0.6 volumes Isopropanol and mix gently by inverting the tubes. Check for DNA precipitation.

10. Spin down for 10 min. at RT.

11. Add 500 μl wash buffer and incubate 10 min. at RT.

12. Carefully remove wash buffer. Don't lose DNA pellet!

13. Briefly centrifuge to collect pellet at bottom of tube - remove any remaining wash buffer.

14. Dry pellet at RT or 50°C to speed up.

15. Add 100 μl ddH2O to dissolve DNA.

16. Store at -20°C until needed.

17. Run electrophoresis for analysis.

Prepared solutions

Buffer: 100 ml: 50 mM Tris/HCl (ph 8.0), 1.8 M NaCl, 50 mM EDTA. Then add 10 mg/ml of CTAB ( 200 mg per 20 ml buffer, final conc. = 1%) and 1 μl/ml 2-mercaptoethanol (20 μl to 20 ml buffer; final conc. = 0.1%).

Wash buffer 100 ml: 200 μl 5M NH4OAc (final conc. = 10 mM), 76.0 ml abs. ethanol (final conc. = 76%), and 23.8 ml of sterilized water.

Bioprotocols: Hop DNA Extraction Protocol

25 Dec 2010 ... Hop DNA Extraction Protocol. 1. Obtain an adequate amount (~ 1g) of fresh hop leaves and crush them with liquid Nitrogen and a small amount ...
bio888.blogspot.com/2010/12/hop-dna-extraction-protocol.html

Robust CTAB-activated charcoal protocol for plant DNA extraction
author：M KRIŽMAN - 2006
Dried hop cones were obtained from the experimental fields (yield 2005) .... Modification of a CTAB DNA extraction protocol for plants ...
fp.unud.ac.id/biotek/wp-content/uploads/biologisel/ekstraksi-dna.pdf

Isolation of plant DNA: A fast, inexpensive, and reliable method

author：P Guillemaut - 1992
Protocol. Isolation of plant DNA. DNA can be isolated from fresh, frozen, dried or lyophilized material without pretreatment of tissue. The procedure ...
www.springerlink.com/index/2656658377412530.pdf

Transmission electron microscopy DNA sequencing

2011-07-01T04:08:00.000-07:00

Transmission electron microscopy DNA sequencing is an emerging third-generation, single-molecule sequencing technology that uses transmission electron microscopy techniques. DNA is visible under the electron microscope; however, it must be labeled with heavy atoms so that the DNA bases can be clearly visualized. In addition, specialized imaging techniques and aberration corrected optics are beneficial for obtaining the resolution required to image the labeled DNA molecule. Transmission electron microscopy DNA sequencing advantageously may provide extremely long read lengths, but it is not yet commercially available.

History

Only a few years aft

er James Watson and Francis Crick deduced the structure of DNA, and nearly two decades before Frederick Sanger published the first method for rapid DNA sequencing, Richard Feynman, an American physicist, envisioned the electron microscope as the tool that would one day allow biologists to “see the order of bases in the DNA chain”. Feynman believed that if the electron microscope could be made powerful enough, then it would become possible to visualize the atomic structure of any and all chemical compounds, including DNA. To this day, despite the invention of a multitude of chemical and fluorescent sequencing technologies, microscopy is still being explored as a means of performing single-molecule DNA sequencing. Two biotechnology companies have conceived of methods for high throughput, direct detection of DNA bases by transmission electron microscopy; however, these studies are still in their infancy and are far from being commercially available. The following progress in these technologies has been reported: 1970 Albert Crewe developed the high-angle annular dark-field imaging (HAADF) imaging technique in a scanning transmission electron microscope. Using this technique, he visualized individual heavy atoms on thin amorphous carbon films. April 2008: ZS Genetics presented its plans for development of a transmission electron microscopy-based single-

molecule sequencing platform at the Cambridge Health-tech Institute (CHI) Sequencing Conference in San Diego, held from 23–24 April 2008.

March 2010: Krivanek and colleagues reported several technical improvements to the HAADF method, including a combination of aberration corrected electron optics and low accelerating voltage. The latter is crucial for imaging biological objects, as it allows to reduce damage by the beam and increase the image contrast for light atoms. As a result, single atom substitutions in a boron nitride monolayer could be imaged. Halcyon Molecular is developing its single-molecule sequencing platform based on the technology utilized in this paper.

September 2010: The Toste research group at University of California, Berkeley, received an Advanced Sequencing Technology Award from the National Human Genome Research Institute to continue research into single-molecule sequencing by transmission electron microscopy, in collaboration with Halcyon Molecular.

Principle

The electron microscope has the capacity to obtain a resolution of up to 100 pm, whereby microscopic biomolecules and structures such as viruses, ribosomes, proteins, lipids, small molecules and even single atoms can be observed.

Although DNA is visible when observed with the electron microscope, the resolution of the image obtained is not high enough to allow for deciphering the sequence of the individual bases, i.e., DNA sequencing. However, upon differential labeling of the DNA bases with heavy atoms or metals, it is possible to both visualize and distinguish between the individual bases. Therefore, electron microscopy in conjunction with differential heavy atom DNA labeling could be used to directly image the DNA in order to determine its sequence.

Procedure of transmission electron microscopy DNA sequencing:

Step 1 – DNA denaturation

As in a standard polymerase chain reaction (PCR), the double stranded DNA molecules to be sequenced must be denatured before the second strand can be synthesized with labeled nucleotides.

Step 2 – Heavy atom labeling

The elements that make up biological molecules (C, H, N, O, P, S) are too light (low atomic number, Z) to be clearly visualized as individual atoms by transmission electron microscopy. To circumvent this problem, the DNA bases can be labeled with heavier atoms (higher Z). Each nucleotide is tagged with a characteristic heavy label, so that they can be distinguished in the transmission electron micrograph.

ZS Genetics proposes using three heavy labels: bromine (Z=35), iodine (Z=53), and trichloromethane (total Z=63). These would appear as differential dark and light spots on the micrograph, and the fourth DNA base would remain unlabeled.

Halcyon Molecular, in collaboration with the Toste group, proposes that purine and pyrimidine bases can be functionalized with platinum diamine or osmium tetraoxide bipyridine, respectively. Heavy metal atoms such as osmium (Z=76), iridium (Z=77), gold (Z=79), or uranium (Z=92) can then form metal-metal bonds with these functional groups to label the individual bases.

Step 3 – DNA alignment on substrate

The DNA molecules must be stretched out on a thin, solid substrate so that order of the labeled bases will be clearly visible on the electron micrograph. Molecular combing is a technique that utilizes the force of a receding air-water interface to extend DNA molecules, leaving them irreversibly bound to a silane layer once dry. This is one means by which alignment of the DNA on a solid substrate may be achieved.

Step 4 – TEM imaging

Electron microscopy image of DNA: ribosomal transcription units of Chrironumus pallidivitatus. The image was recorded with the relatively old technology (ca. 2005).

Transmission electron microscopy (TEM) produces high magnification, high resolution images by passing a beam of electrons through a very thin sample. Whereas atomic resolution has been demonstrated with conventional TEM, further improvement in spatial resolution requires correcting the spherical and chromatic aberrations of the microscope lenses. This has only been possible in scanning transmission electron microscopy where the image is obtained by scanning the object with a finely focused electron beam, in a way similar to a cathode ray tube. However, the achieved improvement in resolution comes together with irradiation of the studied object by much higher beam intensities, the concomitant sample damage and the associated imaging artefacts. Different imaging techniques are applied depending on whether the sample contains heavy or light atoms:

Annular dark-field imaging measures the scattering of electrons as they deflect off the nuclei of the atoms in the transmission electron microscopy sample. This is best suited to samples containing heavy atoms, as they cause more scattering of electrons. The technique has been used to image atoms as light as boron, nitrogen, and carbon; however, the signal is very weak for such light atoms. If annular dark-field microscopy is put to use for transmission electron microscopy DNA sequencing, it will certainly be necessary to label the DNA bases with heavy atoms so that a strong signal can be detected.

Annular bright-field imaging detects electrons transmitted directly through the sample, and measures the wave interference produced by their interactions with the atomic nuclei. This technique can detect light atoms with greater sensitivity than annular dark-field imaging methods. In fact, oxygen, nitrogen, lithium, and hydrogen in crystalline solids have been imaged using annular bright-field electron microscopy. Thus, it is theoretically possible to obtain direct images of the atoms in the DNA chain; however, the structure of DNA is much less geometric than crystalline solids, so direct imaging without prior labeling may not be achievable.

Step 5 – Data analysis

Dark and bright spots on the electron micrograph, corresponding to the differentially labeled DNA bases, are analyzed by computer software.

Applications

Transmission electron microscopy DNA sequencing is not yet commercially available, but the long read lengths that this technology may one day provide will make it useful in a variety of contexts.

De novo genome assembly

When sequencing a genome, it must be broken down into pieces that are short enough to be sequenced in a single read. These reads must then be put back together like a jigsaw puzzle by aligning the regions that overlap between reads; this process is called de novo genome assembly. The longer the read length that a sequencing platform provides, the longer the overlapping regions, and the easier it is to assemble the genome. From a computational perspective, microfluidic Sanger sequencing is still the most effective way to sequence and assemble genomes for which no reference genome sequence exists. The relatively long read lengths provide substantial overlap between individual sequencing reads, which allows for greater statistical confidence in the assembly. In addition, long Sanger reads are able to span most regions of repetitive DNA sequence which otherwise confound sequence assembly by causing false alignments. However, de novo genome assembly by Sanger sequencing is extremely expensive and time consuming. Second generation sequencing technologies, while less expensive, are generally unfit for de novo genome assembly due to short read lengths. In general, third generation sequencing technologies, including transmission electron microscopy DNA sequencing, aim to improve read length while maintaining low sequencing cost. Thus, as third generation sequencing technologies improve, rapid and inexpensive de novo genome assembly will become a reality.

Full haplotypes

haplotype is a series of linked alleles that are inherited together on a single chromosome. DNA sequencing can be used to genotype all of the single nucleotide polymorphisms (SNPs) that constitute a haplotype. However, short DNA sequencing reads often cannot be phased; that is, heterozygous variants cannot be confidently assigned to the correct haplotype. In fact, haplotyping with short read DNA sequencing data requires very high coverage (average >50x coverage of each DNA base) to accurately identify SNPs, as well as additional sequence data from the parents so that Mendelian transmission can be used to estimate the haplotypes. Sequencing technologies that generate long reads, including transmission electron microscopy DNA sequencing, can capture entire haploblocks in a single read. That is, haplotypes are not broken up among multiple reads, and the genetically linked alleles remain together in the sequencing data. Therefore, long reads make haplotyping easier and more accurate, which is beneficial to the field of population genetics.

Copy number variants

Genes are normally present in two copies in the diploid human genome; genes that deviate from this standard copy number are referred to as copy number variants (CNVs). Copy number variation can be benign (these are usually common variants, called copy number polymorphisms) or pathogenic. CNVs are detected by fluorescence in situ hybridization (FISH) or comparative genomic hybridization (CGH). To detect the specific breakpoints at which a deletion occurs, or to detect genomic lesions introduced by a duplication or amplification event, CGH can be performed using a tiling array (array CGH), or the variant region can be sequenced. Long sequencing reads are especially useful for analyzing duplications or amplifications, as it is possible to analyze the orientation of the amplified segments if they are captured in a single sequencing read.

Cancer

Cancer genomics, or oncogenomics, is an emerging field in which high-throughput, second generation DNA sequencing technology is being applied to sequence entire cancer genomes. Analyzing this short read sequencing data encompasses all of the problems associated with de novo genome assembly using short read data. Furthermore, cancer genomes are often aneuploid. These aberrations, which are essentially large scale copy number variants, can be analyzed by second-generation sequencing technologies using read frequency to estimate the copy number. Longer reads would, however, provide a more accurate picture of copy number, orientation of amplified regions, and SNPs present in cancer genomes.

Microbiome sequencing

The microbiome refers the total collection of microbes present in a microenvironment and their respective genomes. For example, an estimated 100 trillion microbial cells colonize the human body at any given time. The human microbiome is of particular interest, as these commensal bacteria are important for human health and immunity. Most of the Earth's bacterial genomes have not yet been sequenced; undertaking a microbiome sequencing project would require extensive de novo genome assembly, a prospect which is daunting with short read DNA sequencing technologies. Longer reads would greatly facilitate the assembly of new microbial genomes.

Advantages and disadvantages

Compared to other second- and third-generation DNA sequencing technologies, transmission electron microscopy DNA sequencing has a number of potential key strengths and weaknesses, which will ultimately determine its usefulness and prominence as a future DNA sequencing technology.

Advantages

Longer read lengths: ZS Genetics has estimated potential read lengths of transmission electron microscopy DNA sequencing to be 10,000 to 20,000 base pairs with a rate of 1.7 billion base pairs per day. Such long read lengths would allow easier de novo genome assembly and direct detection of haplotypes, among other applications.

Lower cost: Transmission electron microscopy DNA sequencing is estimated to cost just US$5,000-US$10,000 per human genome, compared to the more expensive second-generation DNA sequencing alternatives.

No dephasing: Dephasing of the DNA strands due to loss in synchronicity during synthesis is a major problem of second-generation sequencing technologies. For transmission electron microscopy DNA sequencing and several other third-generation sequencing technologies, sychronization of the reads is unnecessary as only one molecule is being read at a time.

Shorter turnaround time: The capacity to read native fragments of DNA renders complex template preparation an unnecessary step in the general workflow of whole genome sequencing. Consequently, shorter turnaround times are possible.

Disadvantages

High capital cost: A transmission electron microscope with sufficient resolution required for transmission electron microscopy DNA sequencing costs approximately US$1,000,000, therefore pursuing DNA sequencing by this method requires a substantial investment.

Technically challenging: Selective heavy atom labeling and attaching and straightening the labeled DNA to a substrate are a serious technical challenge. Further, the DNA sample should be stable to the high vacuum of electron microscope and irradiation by a focused beam of high-energy electrons.

Potential PCR bias and artefacts: Although PCR is only being utilized in transmission electron microscopy DNA sequencing as a means to label the DNA strand with heavy atoms or metals, there could be the possibility of introducing bias in template representation or errors during the single amplification.

Yeast DNA and RNA Methods

2011-07-01T04:07:00.001-07:00

Yeast DNA and RNA Methods

Beta-gal Assay

Bgal filter assay

Bgal liquid assay

Bgal plate overlay assay

Determination of r eplication Timing of yeast by Comparative Hybridization

Determination of replication Timing of yeast by Density Transfer

Determination of r eplication Timing of yeast by Transient Hemimethylation

DNA Replication Techniques

Isolation of yeast DNA by smash and grab method

Liquid Sporulation

Plasmid Rescue from Yeast from Liquid Culture and Clony Rescue

Preparation of Yeast DNA Embedded in Agarose Plugs

Quantitative Mating Assay

Rather Rapid Genomic Prep

RNA Prep

ß-GAL Filter Assay

ß -gal Lift method

Yeast Chromosomal DNA Preparation

Yeast DNA Miniprep Protocol (Haber Lab)

Yeast DNA Preparation by rapid glass bead method

Yeast Genomic DNA Extraction 2-D Gels

Yeast Genomic DNA Isoaltion

Yeast Genomic DNA Miniprep artion

Yeast protocol (for microarray)

Yeast quick plasmid DNA Preparation

Yeast RNA Minipre paration

Databases of Yeast Genetics

2011-07-01T04:06:00.000-07:00

Yeast Genetics

EMS Mutagenesis

EMS mutagenesis of yeast

Generating a Temperature Sensitive Allele

Genome-wide Gene Expression Analysis

Pheromone halo assay (Dohlman Lab)
UV mutagenesis (Corbett Lab)
Replication timing by density transfer (Fangman / Brewer Lab)
beta-Gal reporter gene assay (Dohlman Lab)
beta-Gal filter assay (Dohlman Lab)
beta-Gal filter assay (Breeden Lab)
b-Gal filter assays (Herskowitz Lab)
EMS mutagenesis of yeast (Hahn Lab)
Replication timing by comparative hybridization (Fangman / Brewer Lab)
Replication timing using transient hemimethylation (Fangman / Brewer Lab)
X-Gal agarose overlay assay (Herskowitz Lab)
Procedure for generating ts alleles of NUT2 (Herskowitz Lab)
Yeast Genetics Protocols (Herskowitz Lab)

Yale Genome Analysis Center

Two-Hybrid System

2011-07-01T04:05:00.000-07:00

Brent Lab Two-Hybrid Information

Development of an optimized interaction-mating protocol for large-scale two-hybrid analyses.

GST fusion protein purification from Yeast (Dohlman Lab)

Handling and using insertion libraries

Nature Protocols: Smart-pool-array protocol for a yeast two-hybrid assay.

Performing a hunt by interaction mating (Finely Lab)
The yeast two-hybrid system for beginners (Newman / Collinge Lab)
Two-hybrid system (Millner Lab)
Two-hybrid analysis of genetic regulatory networks (Finely Lab)
Two-hybrid system (Finely Lab)
Two-hybrid system (Gietz Lab)

Two Hybrid System Transformation

Yeast Two-Hybrid : State of the Art (Van Criekinge, Beyaert)

US Scientists Reverse Signs of Aging in Mice

2010-12-04T08:27:00.000-08:00

Elderly mice restored to middle age

Jessica Berman | Washington, DC 01 December 2010

Harvard scientists say they were able to reverse signs of aging in mice by tweaking a gene which protects cells from the harmful, cumulative effects associated with growing old.

Scientists say they have reversed age-related degeneration in mice, resulting in an improvement in the rodents' fertility and the growth of new brain tissue. But it could be some time before the technique might be used in humans.

Fountain of youth

Scientists at Harvard University's Dana-Farber Cancer Institute in Boston report they were able to reverse signs of aging in mice by tweaking a gene that protects cells from the harmful, cumulative effects associated with growing old.

The gene is involved in the production of structures at the tips of DNA chromosomes called telomeres.

Telomeres are like the plastic caps on the ends of shoe laces that keep them from becoming frayed. In the case of chromosomes, the telomeres protect the strands of DNA from environmental assaults such as chemical and radiation exposure.

But every time a cell divides, its telemeres shorten, eventually leading to DNA damage and aging.

In studies with mice, researchers switched off the telomerase gene and watched the rodents rapidly develop age-related impairments.

Eternally young?

However, when they turned the genes back on on, the animals' declines reversed.

"Their fertility was restored. We also saw a big effect on the lining of the intestines and as well as in the brain, which was a little bit unexpected," says lead researcher Mariela Jaskelioff. "We actually saw a decrease in the size of the brains of these mice with premature aging. And we could reverse these by reactivating telomerase."

The mice in the study were at an age equivalent of an 80- or 90-year-old human. Researchers restored them to middle age by turning on the telomerase gene.

Despite the encouraging results, the genetic manipulation is not the secret to eternal youth for humans. Jaskelioff says the telomerase gene is involved in the growth of both normal and cancerous cells.

"The fear is that in humans, adult humans, we accumulate mutations all through our lifetimes," she says. "And if we were to reactivate telomerase in cells that have malignant mutations, then the propensity to develop cancer would probably be exacerbated."

However, according to Jaskelioff, it might be possible to stimulate the telomerase gene for short periods of time in people with a rare disorder which causes premature aging.

Scientists describe how they reversed aging in mice in an article published in the journal Nature Medicine.

Gene therapy 'memory boost hope'

2010-11-29T21:08:00.000-08:00

This research adds a piece to the Alzheimer's puzzle and provides new leads for researchers”

Rebecca Wood

Alzheimer's Research Trust

A gene therapy technique which aims to ease memory problems linked to Alzheimer's Disease has been successfully tested in mice.

US scientists used it to increase levels of a chemical which helps brain cells signal to each other.

This signalling is hindered in Alzheimer's Disease, the journal Nature reported.

The Alzheimer's Research Trust said the study suggested a way to keep nerve cells in the brain communicating,

Ageing populations in many countries around the world mean that Alzheimer's disease and other forms of dementia are set to increase.

Researchers at the Gladstone Institute of Neurological Disease in San Francisco believe that boosting the brain chemical, a neurotransmitter called EphB2, could help reduce or even prevent some of the worst effects of the condition.

Their research suggests that the chemical plays an important role in memory, and is depleted in Alzheimer's patients.

One of the most noticeable features about the brains of Alzheimer's patients is the build-up of "plaques" of a toxic protein called amyloid. Over time this leads to the death of brain cells.

'Thrilled'

However, another characteristic of amyloid is its apparent ability to bind directly to EphB2, reducing the amount available to brain cells, which could in part explain the memory symptoms involved.

To test this idea, they used gene therapy experiments to artificially reduce and increase the amount of available EphB2 in the brains of mice.

When levels of the chemical were reduced, healthy mice developed memory symptoms similar to those seen in mice bred to have a condition similar to Alzheimer's.

Conversely, when the "Alzheimer's" mice were given gene therapy which boosted levels of EphB2, their memory symptoms disappeared.

Dr Lennart Mucke, who led the study, said that his team had been "thrilled" to find this.

"We think that blocking amyloid proteins from binding to EphB2, and enhancing EphB2 levels or functions with drugs might be of benefit in Alzheimer's Disease."

However UK researchers said that the find, while interesting, did not offer a swift answer to Alzheimer's patients.

Rebecca Wood, chief executive of the Alzheimer's Research Trust, said: "Our brains are hugely complex and understanding how they work and become damaged by diseases like Alzheimer's is a massive task.

"This research adds a piece to the Alzheimer's puzzle and provides new leads for researchers.

"It suggests a way to keep nerve cells in the brain communicating, which is vital for thinking and memory."

But she added: "We don't know yet if these findings will lead to a new treatment for Alzheimer's - that's some way off."

(BBC)

New Era for Human Genetics Begins

2010-11-25T07:16:00.000-08:00

1000 Genomes Project focuses on genetic differences which could lead to greater understanding of disease, evolution

Art Chimes | St. Louis, Missouri 27 October 2010

An international effort to build a detailed map of human genetic variation has completed its pilot phase and could shape a new understanding of human evolution and may help in fighting disease.

The 1000 Genomes Project aims to sequence the genetic code of 2,500 people.

A decade ago, scientists made worldwide headlines when they announced they had sequenced the human genome - made a kind of map, in other words, of DNA, the inherited molecule that makes us human. But that was only one genome. Everyone on Earth has a unique genetic makeup, and researchers have now sequenced thousands of individuals' DNA.

The first effort to sequence the human genome came in under budget and ahead of schedule, and the process has gotten progressively cheaper and faster.

"In the last 10 years," said Richard Durbin, co-chair of the 1000 Genomes Project. "DNA sequencing technology has advanced dramatically so it has become feasible to systematically sequence many people to find genetic variants, and build a catalog which we can use as a basis for investigations into disease, genetics, and which variants may be functional."

Getty Images/iStockphoto

Genetic variations are the way your genes differ from other people's. Some variations relate to differences we can see, like eye color. Others may put us at greater risk for disease. Some variations are inherited. Others can be caused by toxic chemicals or radiation or simply by mistakes in copying DNA.

Most genetic variations are found in lots of unrelated people. Scientists have started to investigate possible links between disease and some of these variations, called single nucleotide polymorphisms, or SNPs. The researchers aim to probe deeper.

"The 1000 Genomes Project makes this approach much more complete and much more powerful," said David Altschuler, 1000 Genomes co-chair, "by going down to much lower frequencies, and also broader range of populations and more complete data in each frequency range and each population."

At the University of Washington in Seattle, meanwhile, Evan Eichler and his colleagues have been using a technique to identify pieces of the genome that duplicate other parts of the DNA code. Writing in the journal Science, the researchers describe how they identified more than four million places where they found these duplicates, called copy-number variants.

Eichler says these variants could help identify genes that may be associated with disease that are what he called "inaccessible" using other techniques. He also said it can help improve the understanding of human evolution.

"We think the veil has been lifted for us in terms of a whole new level of genetic diversity. And when we compare these roughly 159 humans that we've analyzed to date, and compared variations they've found in their genomes to that of the great apes, we have the ability, I think pretty clearly, to identify the genes and the gene families which have expanded specifically in our lineage of evolution since we separated from that of chimpanzee and gorilla," Eichler said.

Back at the 1000 Genomes project, co-chair David Altshuler says the organization's work will provide data so scientists can answer questions about the role genes play in health based on facts, not guesswork. "And so rather than speculate," he said, "I think we'd say we are helping to create the foundation to answer that question, and anyone who does speculate, I think is speculating."

By the way, the goal of the 1000 Genomes project isn't to sequence the genetic code of exactly 1,000 people. Instead, the aim is to identify genetic variations that occur in at least one out of every 100 people or one percent. In particular, that will require using genetic material from many thousands of people from all over the world. And it will need to include a lot more geographic diversity. Only a handful of genomes from Latin America and Africa have been sequenced so far.

Researchers May Some Day Treat Depression with Gene Therapy

2010-11-25T07:14:00.000-08:00

Jessica Berman 21 October 2010

Doctors may some day treat patients suffering from major depression with gene therapy. So say scientists who report they are encouraged by human and animal research.

Scientists have identified a protein called p11 in a small region of the brain that plays a role in major depression. The brain region, known as the nucleus accumbens, is responsible for feelings of pleasure and reward.

Researcher Michael Kaplitt of the department of neurological surgery at Presbyterian / Weill Cornell Medical Center in New York, says mice bred without the p11 gene showed signs of severe depression, including passivity when dangled by their tails instead of trying to get away and a disinterest in sugar water, which he says is like candy to mice who normally drink a lot of it.

Kaplitt also says autopsy studies of tissue taken from the brains of people with severe depression showed extremely low levels of p11 in the nucleus accumbens compared to the brains of individuals without depression.

"So if human beings have lower levels of p11 in this area of the brain, if they have depression, and if animals when they have low p11 levels in this area show depression-like behaviors, then that suggests that this might be a very important component of depression; not the only component but it may be a very important component," said Kaplitt.

Using so-called knock-out mice that completely lacked the p11, Kaplitt says researchers inserted a normal copy of the protein into a harmless virus and infused it into the nucleus accumbens of the depressed rodents.

"Now when we restored it to these adult mice, it completely normalized their behaviors; it reversed these depression-like behaviors so that they were back to normal," he said. "So that suggested that if you have low p11 levels in that area, and if that is a cause of depression, that we could potentially reverse it with gene therapy."

Kaplitt and colleagues have also been conducting promising therapy trials with Parkinson's disease patients.

The researchers hope to soon begin gene therapy experiments in patients with major depression who do not respond to anti-depressant medications.

An article on gene therapy for major depression is published in the journal Science Translational Medicine.

Scientists Discover Pain Genes

2010-11-25T07:11:00.000-08:00

Jessica Berman | Washington 11 November 2010

Scientists have discovered hundreds of genes that appear to play a role in determining pain sensitivity. Researchers say slight variations in one pain gene in particular seem to affect how intensely pain is felt.

Under normal circumstances, scientists say pain serves an important biological function; a sharp poke with a needle or knifepoint, or slight burn, causes most people to recoil, protecting them from further harm.

Then there is another type of pain, according to Clifford Woolf a neurobiologist at Children's Hospital in Boston, Massachusetts.

"The other kind of pain is when the fire alarm system is on all the time, and these would be patients who have chronic persistent pain," Woolf explained. "And that is a situation where pain has become a disease in its own right. It's no longer warning of damage; the fire alarm is on all the time and there's no fire."

Scientists say studies of twins show that the degree to which an individual feels pain is largely inherited.

In an effort to identify genes involved in pain, an international team of researchers led by Woolf identified some 600 potential genes in fruit flies which are similar in humans.

Scientists focused on one gene in particular called "Alpha 2 Delta 3."

In a study of 189 healthy volunteers, researchers found reduced sensitivity to heat among participants who had slight alphabet variations to the DNA code within or close to the location of the Alpha 2 Delta 3 gene.

Researchers also found in another study that back pain patients who had the rarer genetic variants were less likely to experience persisting pain after surgery.

By learning the genetic underpinnings of pain, Woolf says it will someday be possible to develop medications to treat a variety of pain syndromes.

"There's pain associated with damage to the nervous system. Pain associated with the inflammatory diseases," neurobiologist Woolf noted. "There's post-operative pain. And each of them operates in slightly different ways, and so there will be different targets and different analgesics required for these different kinds of pain."

Researchers say it may one day be possible to develop genetic risk profiles to determine who is at greatest risk of chronic pain following surgery. Such information could be useful in helping patients decide whether to go forward with an operation.

An article describing the pain genes is published in the journal Cell.

Stem Cell Therapy Gaining Ground in Asia

2010-11-25T07:05:00.000-08:00

Heda Bayron | Hong Kong 25 November 2010

Asians are beginning to warm up to the idea of using their own stem cells to treat a host of illnesses such as heart disease, cystic fibrosis or leukemia. Some parents are preserving their babies' umbilical cords, hoping that as technology advances their children can use the umbilical blood to cure future illnesses.

It is a nightmare for parents to hear their child has developed a disease that requires a bone marrow transplant. For instance, patients with leukemia, a type of blood cancer, sometimes have a hard time finding a bone marrow match.

Scientists say the umbilical cord that attaches a baby to its mother is a rich source of stem cells, which can treat diseases like leukemia. They can be collected immediately after birth and stored in freezers by companies such as Cordlife, which operates cord blood banks in Hong Kong, Singapore, Indonesia, India and the Philippines. If a child needs it, doctors can retrieve cord blood for treatment.

"We're seeing an explosion umbilical cord blood banking as a source of biological insurance for parents in Asia and their children," said Andrew Wu, Cordlife's technical and laboratory director.

Scientists around the world are finding new ways to use cord blood stem cells to treat problems such as spinal cord damage, diabetes, cerebral palsy and heart disease.

At Cordlife, parents pay about $4,000 to keep their children's cord blood for 18 years.

"I'm most excited to see the use of stem cell in therapy becoming a standard of care, where clinicians when they look at a disease would ask, 'What's my stem cell option in terms of therapy? How I can look to stem cells to treat this disease or regenerate this organ or to combat this tumor?'" Wu said.

Asia appears striding toward the use of stem cells for treatment.

Dr. Supachai Chaithiraphan, a professor emeritus of Thailand's Mahidol University and director of the cardiac center at Chao Phya hospital in Bangkok, conducted a clinical trial in 2004 that injected stem cells derived from human blood to treat people with end-stage heart disease.

"Eighty percent showed improvement in terms of New York Heart Association classification and also the Canadian [Cardiac Society] angina classification. So we feel that this group of patients can derive benefit from their own stem cell therapy," Supachai said.

In Asia, there are fewer regulations regarding the use of stem cells than in the United States, which encourages research and clinical uses.

In the U.S., the use of stem cells has been controversial because of ethical concerns over the use of embryonic stem cells - derived from early-stage embryos that develop from human eggs fertilized in a laboratory. Under President Bush, the government limited funding to a few batches of stem cell lines. But the Obama administration has since relaxed those rules.

However, cord blood storage appears to be increasing in the U.S. A new national cord blood bank has been established at Duke University in the state of North Carolina.

Some practitioners, such as Wu worry that Asia's lax regulations may lead to inflated expectations and false promises.

"A lot still needs to go into building this understanding and building appropriate regulations around the use of these stem cells so that the industry as a whole can develop within a legal framework that not only benefits the companies but most importantly benefits the clinicians and the patients at the end of the day," Wu said.

Poor medical facilities in some developing Asian nations also hold back use of stem cells.

But Supachai says in time, stem cell therapy will be more accessible.

"I would foresee that in the near future more doctors would come to realize that this cell therapy is really of help to certain number of patients with certain diseases, in particular heart disease," Supachai said.

The World Health Organization estimates that about 20 million people worldwide will die from cardiovascular disease annually by 2015. The number of people in developing nations suffering from heart disease is expected to rise as incomes increase.

Scientists say DNA provides 'historical archive'

2010-11-25T07:02:00.000-08:00

Edinburgh scientists say they have developed a genetic test that can tell if people's ancestors were from a large populated area or a rural village.

The team found that a person's DNA records provide a "historical archive" of where they are from.

The test can also detect if a person's ancestors were related, such as if they are from a community where marriage between cousins was commonplace.

It could help identify people who are more prone to genetic illnesses.

Gene pool

A team at Edinburgh University analysed the DNA of more than 1,000 people across 51 different ethnic groups, ranging from Europeans to Amazonian tribes, during the study.

They identified those who had inherited the same genetic material from both parents The study found that native South Americans had the highest amount of shared DNA, suggesting that those communities were small and isolated over many generations.

By contrast, African communities had the lowest degree of genetic similarity, indicating a more diverse population over time.

The team believe this could be explained by the fact that humans originated in Africa and so have had the most time to develop a diverse gene pool.

Dr Jim Wilson, Royal Society research fellow at Edinburgh University, said: "The exciting thing about these results is that it shows our genes are recording the history of movements in our population.

"It's like an archive being written in genetic code, so that we can understand the way our populations have developed from the distant past.

"The findings are also important because it highlights those areas of the world where genetic similarity is common and this can be a risk factor for some diseases like cystic fibrosis, which can be caused when you inherit a faulty gene from both parents."

The scientists said DNA records provided a "historical archive" of where people are from

(source: BBC)

Genes Predict Who Will Live to Age 100

2010-07-14T21:05:00.001-07:00

Technique may also help predict disease

Art Chimes | St. Louis, Missouri

Photo: Photos.com

Genes, rather than lifestyle, impact who lives 100 years.

Researchers at Boston University have identified a kind of genetic signature in people who are likely to live to age 100 or older. The technique may also help doctors predict whether you're likely to get a disease, decades before the symptoms show up.

Living a long, healthy life tends to run in families. If your grandparents and parents lived into their 90s and remained relatively healthy until the end, there's a pretty good chance you will, too.

So it's pretty clear genetics plays some role in longevity.

In this study, the research team developed a new statistical way of analyzing the genetic code of people who had reached age 100 as compared with people who had a more typical lifespan. Tom Perls, who heads the New England Centenarian Study, explains what they found.

"We discovered 150 or so genetic markers that can highly predict whether or not a person has the genetic propensity to live to extreme old age."

Using just that large number of genetic markers, the team was able to predict in almost four out of five cases whether a person would live to be 100.

Perls says the key to successfully predicting long life was the sophisticated statistical analysis of many different gene variations that each played some role.

"And that's what this method does - it captures the complexity of the puzzle and the interaction of all these genes together to produce exceptional longevity."

Perls and his colleagues publish their study in the online edition of the journal Science.

The Boston University researcher says this kind of analysis could play a role, not just in predicting who will live longest, but in actually helping people live longer and healthier lives.

In an interview via Skype, Tom Perls said the same technique used to predict long life may also be used to predict whether a person might eventually develop certain diseases. He gave the example of Alzheimer's Disease as one in which genetics plays a role.

"And we think that this methodology can very much be used to capture the bunch of genes that are playing an important role in one's susceptibility to that disease," he said. "And the same can be true, perhaps, for looking at adult-onset diabetes, or cardiovascular disease, or stroke. Again, where I think there is at least a moderate impact from genetic variation."

As the cost of the needed genetic tests continues to decline, he predicts doctors will be able to screen patients for diseases they may not develop until later in life, and recommend ways to avoid them.

Gene Abnormality Found To Predict Childhood Leukemia Relapse

2010-05-06T15:53:00.000-07:00

Scientists have identified mutations in a gene that predict a high likelihood of relapse in children with acute lymphoblastic leukemia (ALL). Although the researchers caution that further research is needed to determine how changes in the gene, called IKZF1 or IKAROS, lead to leukemia relapse, the findings are likely to provide the basis for future diagnostic tests to assess the risk of treatment failure. By using a molecular test to identify this genetic marker in ALL patients, physicians should be better able to assign patients to appropriate therapies.

The findings of the Children Oncology Group (COG) study, led by scientists from St. Jude Children Research Hospital, Memphis, Tenn., the University of New Mexico Cancer Research and Treatment Center, Albuquerque, N.M., and the National Cancer Institute (NCI), part of the National Institutes of Health, appear online Jan. 7, 2009, in the New England Journal of Medicine, and in print on Jan. 29, 2009.

ALL, a cancer of white blood cells, is the most common childhood cancer, in that it is diagnosed in about one in 29,000 children annually. Using currently available therapies, cure rates for ALL are now upwards of 80 percent. However, those therapies carry with them substantial side effects, and even with treatment, only 30 percent of children who experience a relapse of ALL will survive five years. Determining the risk of relapse faced by an individual patient would help physicians tailor treatment intensity appropriately, but until now there has been no good marker for predicting outcome.

"Great progress has been made in recent years in improving the cure rate of childhood ALL," said Stephen Hunger, M.D., chairman of the COG ALL committee and the lead COG investigator on this study. "The findings of this study help us further subdivide those patients who are unlikely to be cured, and identify patients in whom different therapies should be tested."

In the study, researchers analyzed genetic data on leukemia cells obtained at diagnosis from 221 children with high-risk leukemia (i.e., a high chance of relapse) who had been treated in an existing COG study. They conducted their analysis using microarrays and DNA sequencing � technologies which allow researchers to quickly and efficiently identify and analyze multiple genes simultaneously in the same cell. Using these technologies to identify genetic abnormalities in leukemia cells, the investigators examined the DNA of the leukemia cells at the time of diagnosis and then determined if any of the identified genetic changes predicted relapse. To confirm that specific genetic changes were associated with relapse, the scientists also examined a second group of 258 children with ALL who were treated at St. Jude.

"We looked across the genome in an unbiased fashion in an attempt to pull out any genes that were significantly associated with outcome," said Charles Mullighan, M.D., Ph.D., assistant member in the St. Jude Department of Pathology and the paper抯 first author. "From these findings, we identified a group of genetic abnormalities that together predicted poor outcome."

The most significant association was with the deletions or changes in the IKAROS gene. Mutations of IKAROS were shown to identify a subgroup of patients who were treated in the COG study that had a very poor prognosis. The prognostic significance of these genetic alterations was validated in the independent St. Jude patient group, a finding of particular importance since different types of therapies were used in these two groups of patients.

Previous research has shown that the IKAROS gene serves as the blueprint for production of the IKAROS protein, which regulates the activity of many other genes. The IKAROS protein plays an essential role in the development of lymphocytes, the white blood cells that, when changed, give rise to pediatric ALL. The way in which IKAROS abnormalities contribute to the development of relapse remains to be determined.

The study also examined gene expression in the leukemia cells using microarray chips, and found that leukemia cells from patients with IKAROS alterations expressed primitive, stem cell-like genes, suggesting that the cells are less mature and possibly more resistant to the effects of drugs used to treat ALL. "These findings show how detailed analysis of leukemic cells using complementary techniques can enhance our understanding of the genetic basis of leukemia," said co-author Cheryl Willman, M.D., director and CEO, University of New Mexico Cancer Research and Treatment Center.

The researchers also tested whether the presence of IKAROS alterations was associated with levels of minimal residual disease, another measure of treatment response in ALL.

"Measurement of levels of minimal residual disease is widely used to monitor treatment responsiveness and also to alter patients� therapy if they have a very poor response to treatment," said James Downing, M.D., St. Jude scientific director and the paper抯 senior author. "An important analysis we conducted was to see whether identifying the association of IKAROS alterations with poor outcome added anything to just measuring levels of minimal residual disease. And, indeed, it did."

The researchers� analysis indicated that identifying IKAROS alterations may be clinically useful and will complement existing diagnostic tests and measurement of minimal residual disease levels.

While a clinical test for alterations of IKAROS could prove valuable for predicting poor outcomes in children with ALL, complexities remain. There are different types of deletions in the gene, some that involve the entire IKAROS gene and others that involve only parts of the gene. Because the genetic alterations in IKAROS in ALL are not uniform or limited to a single mutation or deletion, it may be necessary to develop a panel of different tests to detect IKAROS lesions and identify which patients are at highest risk for relapse.

This research was done as part of the NCI Therapeutically Applicable Research to Generate Effective Treatments (TARGET) initiative, which seeks to utilize the study of genomics to identify therapeutic targets in order to develop more effective treatments for childhood cancers. The first two cancers being studied in the program are ALL and neuroblastoma, a cancer that arises in immature nerve cells and affects mostly infants and children. Combined, these two cancers account for 3,000 new cases each year, and in both cancers, there are some children who have a very favorable prognosis and others who are at high risk for treatment failure. By determining the genetic factors that distinguish these groups, the hope is that researchers can use this information to improve patient outcomes and develop better treatments, particularly for those in the high-risk group.

"In the long term, our goal is to develop effective therapeutic interventions, directed toward vulnerabilities that leukemia cells acquire as a result of the genomic abnormalities identified through the TARGET initiative," said Malcolm Smith, M.D., Ph.D., of NCI抯 Cancer Therapy Evaluation Program. These are the first results to come out of this initiative. For more information about TARGET, please visithttp://target.cancer.gov

St. Jude Children's Research Hospital
St. Jude Children's Research Hospital is internationally recognized for its pioneering work in finding cures and saving children with cancer and other catastrophic diseases. Founded by late entertainer Danny Thomas and based in Memphis, Tenn., St. Jude freely shares its discoveries with scientific and medical communities around the world. No family ever pays for treatments not covered by insurance, and families without insurance are never asked to pay. For more information, please visit www.stjude.org.

The Children抯 Oncology Group/CureSearch
Children抯 Oncology Group (COG), the world抯 largest cooperative pediatric cancer research organization, which includes every recognized pediatric cancer program in North America, comprises a network of more than 5,000 physician, nurse, and other clinical and laboratory investigators whose collaboration in clinical and translational research has turned childhood cancer from a virtually incurable disease to one with an overall cure rate approaching 80 percent. COG is committed to conquering childhood cancer through scientific discovery and compassionate care. For more information, please visit www.childrensoncologygroup.org

The University of New Mexico Cancer Research and Treatment Center
The UNM Cancer Center is New Mexico抯 only National Cancer Institute-designated cancer center, and is home to the state抯 largest and most experienced team of cancer experts with 81 board-certified oncology physicians and more than 120 research scientists, supported by more than $50 million in grants annually. As the Official Cancer Center of the State of New Mexico, the Center served 7,600 new patients last year in 84,000 patient visits, treating nearly half of all adults with cancer in the state and virtually all the children.

The National Cancer Institute

NCI leads the National Cancer Program and the NIH effort to dramatically reduce the burden of cancer and improve the lives of cancer patients and their families, through research into prevention and cancer biology, the development of new interventions, and the training and mentoring of new researchers. For more information about cancer, please visit the NCI Web site at http://www.cancer.gov or call NCI's Cancer Information Service at 1-800-4-CANCER (1-800-422-6237). The National Institutes of Health

The National Institutes of Health (NIH) — The Nation's Medical Research Agency — includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. It is the primary federal agency for conducting and supporting basic, clinical and translational medical research, and it investigates the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.

Reference: Mullighan CG, Su X, Zhang J, Radtke I, Phillips LAA, Miller CB, Ma J, Liu W, Cheng C, Schulman BA, Harvey RC, Chen I, Clifford RJ, Carroll WL, Reaman G, Bowman WP, Devidas M, Gerhard DS, Yang W, Relling MV, Shurtleff SA, Campana D, Borowitz MJ, Pui C, Smith M, Hunger SP, Willman CL, Downing JR, and the Children's Oncology Group. Deletion of IKZF1 and Prognosis in Acute Lymphoblastic Leukemia. NEJM. Vol. 360, No.

DNA&RNA Databases and Tools

2010-05-06T04:55:00.000-07:00

Databases

BioSystems

Database that groups biomedical literature, small molecules, and sequence data in terms of biological relationships.

Database of Expressed Sequence Tags (dbEST)

A divison of GenBank that contains short single-pass reads of cDNA (transcript) sequences. dbEST can be searched directly through the Nucleotide EST Database.

Database of Genome Survey Sequences (dbGSS)

A division of GenBank that contains short single-pass reads of genomic DNA. dbGSS can be searched directly through the Nucleotide GSS Database.

GenBank

The NIH genetic sequence database, an annotated collection of all publicly available DNA sequences. GenBank is part of the International Nucleotide Sequence Database Collaboration, which comprises the DNA DataBank of Japan (DDBJ), the European Molecular Biology Laboratory (EMBL), and GenBank at NCBI. These three organizations exchange data on a daily basis. GenBank consists of several divisions, most of which can be accessed through the Nucleotide database. The exceptions are the EST and GSS divisions, which are accessed through the Nucleotide EST and Nucleotide GSS databases, respectively.

NCBI Website Search

A database of static NCBI web pages, documentation, and online tools. These pages include such content as specialized online sequence analysis tools, back issues of newsletters, legacy resource description pages, sample code, and other miscellaneous resources. Searching this database is equivalent to a site search tool for the whole NCBI web site. FTP site is not covered.

Nucleotide Database

A collection of nucleotide sequences from several sources, including GenBank, RefSeq, the Third Party Annotation (TPA) database, and PDB. Searching the Nucleotide Database will yield available results from each of its component databases.

PopSet

Database of related DNA sequences that originate from comparative studies: phylogenetic, population, environmental and, to a lesser degree, mutational. Each record in the database is a set of DNA sequences. For example, a population set provides information on genetic variation within an organism, while a phylogenetic set may contain sequences, and their alignment, of a single gene obtained from several related organisms.

Probe

A public registry of nucleic acid reagents designed for use in a wide variety of biomedical research applications, together with information on reagent distributors, probe effectiveness, and computed sequence similarities.

Reference Sequence (RefSeq)

A collection of curated, non-redundant genomic DNA, transcript (RNA), and protein sequences produced by NCBI. RefSeqs provide a stable reference for genome annotation, gene identification and characterization, mutation and polymorphism analysis, expression studies, and comparative analyses. The RefSeq collection is accessed through the Nucleotide and Protein databases.

Sequence Read Archive (SRA)

The Sequence Read Archive (SRA) stores sequencing data from the next generation of sequencing platforms including Roche 454 GS System®, Illumina Genome Analyzer®, Life Technologies AB SOLiD System® , Helicos Biosciences Heliscope®, Complete Genomics®, and Pacific Biosciences SMRT®

Third Party Annotation (TPA) Database

A database that contains sequences built from the existing primary sequence data in GenBank. The sequences and corresponding annotations are experimentally supported and have been published in a peer-reviewed scientific journal. TPA records are retrieved through the Nucleotide Database.

Trace Archive

A repository of DNA sequence chromatograms (traces), base calls, and quality estimates for single-pass reads from various large-scale sequencing projects.

Tools

Batch Entrez

Allows you to retrieve records from many Entrez databases by uploading a file of GI or accession numbers from the Nucleotide or Protein databases, or a file of unique identifiers from other Entrez databases. Search results can be saved in various formats directly to a local file on your computer.

BLAST (Basic Local Alignment Search Tool)

Finds regions of local similarity between biological sequences. The program compares nucleotide or protein sequences to sequence databases and calculates the statistical significance of matches. BLAST can be used to infer functional and evolutionary relationships between sequences as well as to help identify members of gene families.

E-Utilities

Tools that provide access to data within NCBI's Entrez system outside of the regular web query interface. They provide a method of automating Entrez tasks within software applications. Each utility performs a specialized retrieval task, and can be used simply by writing a specially formatted URL.

Genome Workbench

An integrated application for viewing and analyzing sequence data. With Genome Workbench, you can view data in publically available sequence databases at NCBI, and mix these data with your own data.

Influenza Virus

Presents data from the NIAID Influenza Genome Sequencing Project and from GenBank, and provides tools for flu sequence analysis, annotation and submission to GenBank. It also provides links to other flu sequence resources, and publications and general information about flu viruses.

VecScreen

A system for quickly identifying segments of a nucleic acid sequence that may be of vector origin. VecScreen searches a query sequence for segments that match any sequence in a specialized non-redundant vector database (UniVec).

Downloads

BLAST (Stand-alone)

BLAST executables for local use are provided for Solaris, LINUX, Windows, and MacOSX systems. See the README file in the ftp directory for more information. Pre-formatted databases for BLAST nucleotide, protein, and translated searches also are available for downloading under the db subdirectory.

FTP: GenBank

This site contains files for all sequence records in GenBank in the default flat file format. The files are organized by GenBank division, and the full contents are described in the README.genbank file.

FTP: RefSeq

This site contains all nucleotide and protein sequence records in the Reference Sequence (RefSeq) collection. The "release" directory contains the most current release of the complete collection, while data for selected organisms (such as human, mouse and rat) are available in separate directories. Data are available in FASTA and flat file formats. See the README file for details.

FTP: UniVec

This site contains the UniVec and UniVec_Core databases in FASTA format. See the README.uv file for details.

Submissions

BankIt

A web-based sequence submission tool for one or a few submissions, designed to make the submission process quick and easy.

Barcode Submission

Tool to submit Barcodes, short nucleotide sequences from a standard genetic locus for use in species identification.

Sequin

A stand-alone software tool developed by the NCBI for submitting and updating entries to public sequence databases (GenBank, EMBL, or DDBJ). It is capable of handling simple submissions that contain a single short mRNA sequence, complex submissions containing long sequences, multiple annotations, segmented sets of DNA, as well as sequences from phylogenetic and population studies with alignments. For simple submission, use the online submission tool BankIt instead.

tbl2asn

A command-line program that automates the creation of sequence records for submission to GenBank using many of the same functions as Sequin. It is used primarily for submission of complete genomes and large batches of sequences.

Xinjiang discovery provides intriguing DNA link

2010-05-05T05:11:00.000-07:00

CHANGCHUN, April 29 (Xinhua) -- The DNA of some 4,000 year-old bodies unearthed five years ago in Xinjiang, in northwest China, provides scientific evidence of early intermingling between people of European and Asian origin.

Zhou Hui, a professor of life science and her team discovered that some of the earliest inhabitants of the Tarim Basin in the Taklamakan Desert were of European and Siberian descent.

The basin, where hundreds of well-preserved mummies have been found since the 1980s, has attracted great attention from scientists worldwide.

Professor Victor Mair of Pennsylvania University claimed in 2006, "From around 1800 B.C. the earliest mummies in the Tarim Basin were exclusively Caucasoid, or Europoid," after he studied DNA samples derived from five bodies unearthed in the basin.

However, Professor Jin Li of Shanghai-based Fudan University, announced in 2007 that the mummies' DNA in the basin's Loulan area, including the 3,800-year-old Loulan Beauty, indicated East Asian, even South Asian origin.

Many archaeologists have accepted that people living in the basin as early as 3,800 years ago, or the Bronze Age, were of European descent, with Asians, mainly from east Asia, only arriving during the Iron Age, Zhou said. "But when the population from Europe and Asia began 'intermarrying' in the area still remains a mystery," she added.

Zhou and her team got DNA samples from the bones and teeth of 20 mummies, around 4,000-year-old. They were all excavated at the Xiaohe cemetery in the basin in 2004 and 2005.

The analyzed DNA profiles included the mitochondrial DNA, which is exclusively passed down through the mother, and the Y chromosome, passed down from father to son.

We found that DNA from five of the seven males derived from their mother, belonged to a lineage that came from Siberia, most likely from south or eastern Siberia, while their Y chromosome indicated European ancestry, Li Chunxiang, another researcher with the team, told Xinhua.

The seven males' Y chromosome had similarities to ancient Europeans who wandered the Eurasian Steppe, stretching roughly 3,000 miles from west to east, mainly in Central Asia.

People of the lineage can be found now in Eastern Europe, Central Asia and Siberia, but rarely in East Asia, Li said.

The mitochondrial DNA of five males and the nine other mummies (four females and five mummies whose gender is unknown) indicated they were related to an ancient lineage that can now be found mostly in modern Siberia, East Asia and Central Asia, Li said.

Their maternal lineage could be traced to Asian populations most likely lived in south Siberia, she said.

Two other females' DNA indicated their maternal ancestors had come from Western Europe.

"Our finding show the European and Siberian tribes began socializing with each other, even intermarrying, almost 4,000 years ago," Zhou said.

But scholars said the Europeans and Siberians might have met and intermarried outside the basin before their immigration into the basin.

"The civilization of the Tarim Basin, according to archaeological findings, arose very late. The 4,000-year-old mummies we found in Xiaohe are believed to be among the earliest inhabitants in the basin. But the Xiaohe people's DNA lineages are over 10,000 years old," Li said.

DNA with both European and Asian markings was also found in south Siberia. People of European origin had spread eastward into that region during the Bronze Age, she said.

The Xiaohe cemetery, 175 km west of the ancient city of Loulan, is located on the ancient Silk Road, once a booming trade route traversing the Asian continent.

The burial ground, with 167 graves, was first explored by Folke Bergman, a Swedish archaeologist in 1934. But it "vanished" until the Xinjiang Archaeological Institute rediscovered it in 2000, Zhou said.

The excavation of the cemetery began in 2002, but only experts with the institute and the Research Center for Chinese Frontier Archaeology of Jilin University were authorized to unearth the lowest layer where the oldest mummies were buried.

"We found 41 graves in this layer, and 37 of them had human remains. The corpses were lying in bottom-up-boat-like coffins. They all had distinctive European appearances and were well-preserved thanks to the dry air and good drainage." She said.

Some mummies unearthed in the Tarim Basin are displayed in a number of museums in Xinjiang, said Idelis Abdurisulu, former director with the Institute of Cultural and Historical Relics and Archaeology of Xinjiang Uygur Autonomous Region.

"The regional museum has six or seven mummies, while others are scattered around Xinjiang in some smaller museums," he said.

In late March, the Bowers Museum in Santa Ana in California began exhibiting two of the Tarim Basin mummies, including Xiaohe Beauty, a 3,800-year-old female, and Qiemo Baby, an infant aged eight to 10 months who died about 2,800 years ago.

Scientists hail 'revolutionary' kidney gene find

2010-04-13T06:57:00.001-07:00

Chronic kidney disease causes the organs to function less effectivel

The identification of 20 genes which could help explain the causes of kidney disease could one day "revolutionise" treatment, researchers say.

Chronic kidney disease affects about one in 10 adults and can require dialysis or even an organ transplant.

The genes identified by the international team of researchers control kidney functions such as filtering waste from the blood.

Experts said the Nature Genetics study was "a great breakthrough".

Chronic kidney disease (CKD) is a long-term condition in which the kidneys progressively lose their function.

These are still early days but it is truly a great breakthrough

Charles Kernahan, Kidney Research UK

People tend not to notice symptoms, which can include swollen ankles and hands or blood in the urine, until the condition is advanced.

It is linked to ageing - about one in five men and one in four women aged between 65 and 74 will have some degree of CKD.

The most common cause of CKD is damage caused by other long-term conditions, such as diabetes and high blood pressure.

It was known there was a genetic component to the disease, but not which genes were involved.

'First step'

In this study, an international team of scientists, including researchers at the University of Edinburgh, looked at the genes of nearly 70,000 people across Europe.

They found 13 new genes that influence renal function and seven others that affect the production and secretion of creatinine - a chemical waste molecule that is generated from muscle metabolism and filtered through the kidneys.

Dr Jim Wilson, a geneticist at the University of Edinburgh who worked on the study, said: "This work could revolutionise the treatment of kidney disease in the future - but this will take some time.

"It's a very critical first step towards a completely new understanding of the biology behind CKD. Transferring what we've found into clinical benefits will take some years."

Charles Kernahan, chief executive of the charity Kidney Research UK, said "These are still early days but it is truly a great breakthrough.

"No-one knows who will be affected or when kidney disease may strike next, so even more research needs to be funded to help us tackle this challenge."

(Source: BBC Science and Technology)

Autosomal dominant vs Autosomal recessive

2010-04-13T06:47:00.000-07:00

Autosomal dominant

Main article: Autosomal dominant#Autosomal dominant gene

Only one mutated copy of the gene will be necessary for a person to be affected by an autosomal dominant disorder. Each affected person usually has one affected parent. There is a 50% chance that a child will inherit the mutated gene. Conditions that are autosomal dominant often have low penetrance, which means that although only one mutated copy is needed, a relatively small proportion of those who inherit that mutation go on to develop the disease. Examples of this type of disorder are Huntington's disease, Neurofibromatosis 1, Marfan Syndrome, Hereditary nonpolyposis colorectal cancer, and Hereditary multiple exostoses, which is a highly penetrant autosomal dominant disorder. Birth defects are also called congenital anomalies.

Autosomal recessive

Main article: Autosomal dominant#Autosomal recessive allele

Two copies of the gene must be mutated for a person to be affected by an autosomal recessive disorder. An affected person usually has unaffected parents who each carry a single copy of the mutated gene (and are referred to as carriers). Two unaffected people who each carry one copy of the mutated gene have a 25% chance with each pregnancy of having a child affected by the disorder. Examples of this type of disorder are cystic fibrosis, sickle-cell disease (also partial sickle-cell disease),Tay-Sachs disease, Niemann-Pick disease, spinal muscular atrophy, and Dry (otherwise known as "rice-brand") earwax.

Fossil Hunters and Their Amazing Achievements

2010-04-13T04:36:00.000-07:00

9-Year-Old Fossil Hunter Finds 2-Million Old Human

9-Year-Old Fossil Hunter Finds 2-Million Old Human by Mitch Marconi A 9-year-old boy reportedly changed all though of evolution by finding a 2 million year old fossil. According to reports, Matthew Berger, found a fossilized collarbone of a child who ...

www.postchronicle.com/news/original/article_212295261.shtml ·

'Fossil hunter finds 140-million-year-old spider's web'…

http://www.telegraph.co.uk/science/science-news/6467024/Fossil-hunter-finds-140-million-year-old-spiders-web.html The tiny tangled filaments date back 140 million years and are linked to each other in the roughly circular pattern familiar to ...

richarddawkins.net/articles/4556 ·

Nine-Year-Old Fossil Hunter Finds New Species of Human…

Rescue Workers at Twin Towers Show Lung Problems 7 Years After 9/11 Attack ... The Cradle of Humankind, located 40 kilometers (25 miles) outside of Johannesburg, is also the place where the more than 2 million-year-old fossil of Australopithecus africanus

www.bloomberg.com/apps/news?pid=20601124&sid=aqFpdCaWxzl4

Man gets 60 days for dinosaur bones theft

... raptor fossil from a ranch in northern Montana. He is scheduled to be sentenced on July 9 in a separate federal case involving more fossils taken from Bureau of Land Management land. In 2000, Murphy discovered a mummified, 77-million-year-old ...

www.chinadaily.com.cn/world/2009-06/03/content_7973177.htm ·

FOSSIL HUNTER MARY LEAKEY DIES AT 83.(News ...

FOSSIL HUNTER MARY LEAKEY DIES AT 83.(News)(Obituary) ... find Seattle Post-Intelligencer articles. Mary Leakey, the world famous fossil hunter who in ... Mary Leakey and her husband, anthropologist Louis Leakey, who died in 1972 ...

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Fossil Hunter Presentations

The FOSSIL HUNTER© is sure to capture your attention! Your students will see a myriad of fossils, learn first hand what fossils are, how they are formed and many ... To close the presentation each child receives a genuine 12 million year old fossil ... chicago illinois puerto rican festival

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Nine-Year-Old Fossil Hunter Finds New Species of Human…

Nine-Year-Old Fossil Hunter Finds New Species of Human Ancestor Newsvine 2010-04-10 ... Is 2-million-year-old African fossil the missing link in human evolution? 2010-04-10 Newstrack India London, Apr 9 (ANI): Suggestions that the newly found ...

article.wn.com/view/2010/04/10/NineYearOld_Fossil_Hunter... ·

9-year-old Fossil Hunter Finds New Species of Human ...

A 9-year-old fossil hunter may have opened a new chapter in the evolutionary story of mankind when he found the fossilized collarbone of a child who lived almost - 9-year-old Fossil Hunter Finds ...

celebglitz.com/38039/Celebrity-Gossip/9-year-old-fossil... ·

Nine-Year-Old Fossil Hunter Finds New Species of Human…

Nine-Year-Old Fossil Hunter Finds New Species of Human Ancestor April 08, 2010, 10:15 AM EDT ... April 8 (Bloomberg) -- A 9-year-old boy who wandered from his father’s side may have opened a new chapter in the evolutionary story of mankind ...

www.businessweek.com/news/2010-04-08/nine-year-old-fossil...

50-million-year-old fossil horse unearthed

50-million-year-old fossil horse unearthed KEMMERER, Wyo. (AP)--Wyoming has lots of horses, wild horses, quarter horses and pack horses--all kinds of horses. ... As a fossil hunter for 30 years, Tynsky has also found a 13-foot crocodile some 20 ...

www.hpj.com/.../2004/jun04/jun14/50-million-year-oldfossilho.CFM ·

9-year-old Fossil Hunter Finds New Species of Human ...

A 9-year-old fossil hunter may have opened a new chapter in the evolutionary story of mankind when he found the fossilized collarbone of a child who lived almost - 9-year-old Fossil Hunter Finds ...

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Nine-Year-Old Fossil Hunter Finds New Species of Human…

www.businessweek.com/news/2010-04-08/nine-year-old-fossil... ·

50-million-year-old fossil horse unearthed

www.hpj.com/.../2004/jun04/jun14/50-million-year-oldfossilho.CFM ·

D.C.'s Youngest Fossil Hunter | NBC Washington ...

But a local 9-year old girl, Gabrielle Block, is having the last laugh. She snatched up a 100-million-year-old tailbone out of the Dino Park last week, reports the Post. ... http://www.nbcwashington.com/news/local-beat/DCs-Youngest-Fossil-Hunter .

www.nbcwashington.com/news/local-beat/DCs-Youngest-Fossil...

9-Year-Old Finds Dinosaur Fossil | Geology.com

9-Year-Old Finds Dinosaur Fossil November 28, 2009 | MyFoxDC.com A 9-year-old girl from Annandale, Maryland found a fragment of a dinosaur vertebrae at a newly-opened dinosaur park where visitors can help paleontologists. ... Fossil ...

geology.com/news/2009/9-year-old-finds-dinosaur-fossil.shtml ·

The Fossil Hunter (0230611567) EMLING - Palgrave ...

The child of a poor family, Mary became a fossil hunter, inspiring the tongue-twister, “She Sells Sea Shells by the Seashore.” ... From Palgrave Macmillan Pub date: Oct 2009 256 pages Size 6-1/8" x 9-1/4" $27.00 - Hardcover (0-230-61156-7) ...

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FARK.com: (2317360) 100-million-year-old fossil of ...

100-million-year-old fossil of stingray fails to sell at auction; provides media with opportunity to remind us that Steve Irwin is still dead ( ... How can the fossil be 100 million years old when the earth itsself is less the 100 thousand years old??? ...

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Get exclusive content and interact with "The Fossil Hunter" right from Facebook. Join Facebook to create your own Page or to start connecting with friends. ... January 9 at 9:48am ... Imagine the shock caused by these monster creatures ...

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Soft tissue taken from 68 million-year-old…

Soft tissue taken from 68 million-year-old Tyrannosaurus rex fossil yields original protein ... 10 hours ago | 5 / 5 (9) | 2 | (PhysOrg.com) -- Scientists funded by the Biotechnology and Biological Sciences Research Council (BBSRC) at ... The hunter ...

www.physorg.com/news95606831.html ·

47M-Year-Old Fossil Evolutionary 'Aunt' to Humans

Mar 31, 10 9:12 PM CDT ... Scientists have discovered the oldest intact primate fossil on record, ABC News reports. Nicknamed “Ida,” the 47-million-year-old lemur-like creature had opposable thumbs, fingernails instead of claws, and ...

www.newser.com/story/59501/47m-year-old-fossil-evolutionary... ·

What information about a genetic condition can statistics provide?

2010-04-05T06:54:00.000-07:00

Statistical data can provide general information about how common a condition is, how many people have the condition, or how likely it is that a person will develop the condition. Statistics are not personalized, however—they offer estimates based on groups of people. By taking into account a person’s family history, medical history, and other factors, a genetics professional can help interpret what statistics mean for a particular patient.

Some statistical terms are commonly used when describing genetic conditions and other disorders. These terms include:

Common statistical terms
Statistical term	Description	Examples
Incidence	The incidence of a gene mutation or a genetic disorder is the number of people who are born with the mutation or disorder in a specified group per year. Incidence is often written in the form “1 in [a number]” or as a total number of live births.	About 1 in 200,000 people in the United States are born with syndrome A each year. An estimated 15,000 infants with syndrome B were born last year worldwide.
Prevalence	The prevalence of a gene mutation or a genetic disorder is the total number of people in a specified group at a given time who have the mutation or disorder. This term includes both newly diagnosed and pre-existing cases in people of any age. Prevalence is often written in the form “1 in [a number]” or as a total number of people who have a condition.	Approximately 1 in 100,000 people in the United States have syndrome A at the present time. About 100,000 children worldwide currently have syndrome B.
Mortality	Mortality is the number of deaths from a particular disorder occurring in a specified group per year. Mortality is usually expressed as a total number of deaths.	An estimated 12,000 people worldwide died from syndrome C in 2002.
Lifetime risk	Lifetime risk is the average risk of developing a particular disorder at some point during a lifetime. Lifetime risk is often written as a percentage or as “1 in [a number].” It is important to remember that the risk per year or per decade is much lower than the lifetime risk. In addition, other factors may increase or decrease a person’s risk as compared with the average.	Approximately 1 percent of people in the United States develop disorder D during their lifetimes. The lifetime risk of developing disorder D is 1 in 100.

How are genetic conditions and genes named?

2010-04-05T06:37:00.000-07:00

Naming genetic conditions

Genetic conditions are not named in one standard way (unlike genes, which are given an official name and symbol by a formal committee). Doctors who treat families with a particular disorder are often the first to propose a name for the condition. Expert working groups may later revise the name to improve its usefulness. Naming is important because it allows accurate and effective communication about particular conditions, which will ultimately help researchers find new approaches to treatment.

Disorder names are often derived from one or a combination of sources:
The basic genetic or biochemical defect that causes the condition (for example, alpha-1 antitrypsin deficiency);

One or more major signs or symptoms of the disorder (for example, sickle cell anemia);

The parts of the body affected by the condition (for example, retinoblastoma);
The name of a physician or researcher, often the first person to describe the disorder (for example, Marfan syndrome, which was named after Dr. Antoine Bernard-Jean Marfan);

A geographic area (for example, familial Mediterranean fever, which occurs mainly in populations bordering the Mediterranean Sea); or

The name of a patient or family with the condition (for example, amyotrophic lateral sclerosis, which is also called Lou Gehrig disease after a famous baseball player who had the condition).

Disorders named after a specific person or place are called eponyms. There is debate as to whether the possessive form (e.g., Alzheimer’s disease) or the nonpossessive form (Alzheimer disease) of eponyms is preferred. As a rule, medical geneticists use the nonpossessive form, and this form may become the standard for doctors in all fields of medicine.

Naming genes

The HUGO Gene Nomenclature Committee (HGNC) designates an official name and symbol (an abbreviation of the name) for each known human gene. Some official gene names include additional information in parentheses, such as related genetic conditions, subtypes of a condition, or inheritance pattern. The HGNC is a non-profit organization funded by the U.K. Medical Research Council and the U.S. National Institutes of Health. The Committee has named more than 13,000 of the estimated 20,000 to 25,000 genes in the human genome.

During the research process, genes often acquire several alternate names and symbols. Different researchers investigating the same gene may each give the gene a different name, which can cause confusion. The HGNC assigns a unique name and symbol to each human gene, which allows effective organization of genes in large databanks, aiding the advancement of research. For specific information about how genes are named, refer to the HGNC’s Guidelines for Human Gene Nomenclature .

What are complex or multifactorial disorders?

2010-04-05T06:36:00.002-07:00

Researchers are learning that nearly all conditions and diseases have a genetic component. Some disorders, such as sickle cell anemia and cystic fibrosis, are caused by mutations in a single gene. The causes of many other disorders, however, are much more complex. Common medical problems such as heart disease, diabetes, and obesity do not have a single genetic cause—they are likely associated with the effects of multiple genes in combination with lifestyle and environmental factors. Conditions caused by many contributing factors are called complex or multifactorial disorders.

Although complex disorders often cluster in families, they do not have a clear-cut pattern of inheritance. This makes it difficult to determine a person’s risk of inheriting or passing on these disorders. Complex disorders are also difficult to study and treat because the specific factors that cause most of these disorders have not yet been identified. By 2010, however, researchers predict they will have found the major contributing genes for many common complex disorders.

Can changes in mitochondrial DNA affect health and development?

2010-04-05T06:36:00.001-07:00

Mitochondria are structures within cells that convert the energy from food into a form that cells can use. Although most DNA is packaged in chromosomes within the nucleus, mitochondria also have a small amount of their own DNA (known as mitochondrial DNA or mtDNA). In some cases, inherited changes in mitochondrial DNA can cause problems with growth, development, and function of the body’s systems. These mutations disrupt the mitochondria’s ability to generate energy efficiently for the cell.

Conditions caused by mutations in mitochondrial DNA often involve multiple organ systems. The effects of these conditions are most pronounced in organs and tissues that require a lot of energy (such as the heart, brain, and muscles). Although the health consequences of inherited mitochondrial DNA mutations vary widely, frequently observed features include muscle weakness and wasting, problems with movement, diabetes, kidney failure, heart disease, loss of intellectual functions (dementia), hearing loss, and abnormalities involving the eyes and vision.

Mitochondrial DNA is also prone to noninherited (somatic) mutations. Somatic mutations occur in the DNA of certain cells during a person’s lifetime, and typically are not passed to future generations. Because mitochondrial DNA has a limited ability to repair itself when it is damaged, these mutations tend to build up over time. A buildup of somatic mutations in mitochondrial DNA has been associated with some forms of cancer and an increased risk of certain age-related disorders such as heart disease, Alzheimer disease, and Parkinson disease. Additionally, research suggests that the progressive accumulation of these mutations over a person’s lifetime may play a role in the normal process of aging.

Can changes in the structure of chromosomes affect health and development?

2010-04-05T06:35:00.000-07:00

Changes that affect the structure of chromosomes can cause problems with growth, development, and function of the body’s systems. These changes can affect many genes along the chromosome and disrupt the proteins made from those genes.

Structural changes can occur during the formation of egg or sperm cells, in early fetal development, or in any cell after birth. Pieces of DNA can be rearranged within one chromosome or transferred between two or more chromosomes. The effects of structural changes depend on their size and location, and whether any genetic material is gained or lost. Some changes cause medical problems, while others may have no effect on a person’s health.
Changes in chromosome structure include:

Translocations

A translocation occurs when a piece of one chromosome breaks off and attaches to another chromosome. This type of rearrangement is described as balanced if no genetic material is gained or lost in the cell. If there is a gain or loss of genetic material, the translocation is described as unbalanced.

Deletions

Deletions occur when a chromosome breaks and some genetic material is lost. Deletions can be large or small, and can occur anywhere along a chromosome.

Duplications

Duplications occur when part of a chromosome is copied (duplicated) too many times. This type of chromosomal change results in extra copies of genetic material from the duplicated segment.

Inversions

An inversion involves the breakage of a chromosome in two places; the resulting piece of DNA is reversed and re-inserted into the chromosome. Genetic material may or may not be lost as a result of the chromosome breaks. An inversion that involves the chromosome’s constriction point (centromere) is called a pericentric inversion. An inversion that occurs in the long (q) arm or short (p) arm and does not involve the centromere is called a paracentric inversion.

Isochromosomes

An isochromosome is a chromosome with two identical arms. Instead of one long (q) arm and one short (p) arm, an isochromosome has two long arms or two short arms. As a result, these abnormal chromosomes have an extra copy of some genes and are missing copies of other genes.

Dicentric chromosomes

Unlike normal chromosomes, which have a single constriction point (centromere), a dicentric chromosome contains two centromeres. Dicentric chromosomes result from the abnormal fusion of two chromosome pieces, each of which includes a centromere. These structures are unstable and often involve a loss of some genetic material.

Ring chromosomes

Ring chromosomes usually occur when a chromosome breaks in two places and the ends of the chromosome arms fuse together to form a circular structure. The ring may or may not include the chromosome’s constriction point (centromere). In many cases, genetic material near the ends of the chromosome is lost.

Many cancer cells also have changes in their chromosome structure. These changes are not inherited; they occur in somatic cells (cells other than eggs or sperm) during the formation or progression of a cancerous tumor.

Can changes in the number of chromosomes affect health and development?

2010-04-05T06:34:00.000-07:00

Human cells normally contain 23 pairs of chromosomes, for a total of 46 chromosomes in each cell. A change in the number of chromosomes can cause problems with growth, development, and function of the body’s systems. These changes can occur during the formation of reproductive cells (eggs and sperm), in early fetal development, or in any cell after birth. A gain or loss of chromosomes from the normal 46 is called aneuploidy.

A common form of aneuploidy is trisomy, or the presence of an extra chromosome in cells. “Tri-” is Greek for “three”; people with trisomy have three copies of a particular chromosome in cells instead of the normal two copies. Down syndrome is an example of a condition caused by trisomy. People with Down syndrome typically have three copies of chromosome 21 in each cell, for a total of 47 chromosomes per cell.

Monosomy, or the loss of one chromosome in cells, is another kind of aneuploidy. “Mono-” is Greek for “one”; people with monosomy have one copy of a particular chromosome in cells instead of the normal two copies. Turner syndrome is a condition caused by monosomy. Women with Turner syndrome usually have only one copy of the X chromosome in every cell, for a total of 45 chromosomes per cell.

Rarely, some cells end up with complete extra sets of chromosomes. Cells with one additional set of chromosomes, for a total of 69 chromosomes, are called triploid. Cells with two additional sets of chromosomes, for a total of 92 chromosomes, are called tetraploid. A condition in which every cell in the body has an extra set of chromosomes is not compatible with life.

In some cases, a change in the number of chromosomes occurs only in certain cells. When an individual has two or more cell populations with a different chromosomal makeup, this situation is called chromosomal mosaicism. Chromosomal mosaicism occurs from an error in cell division in cells other than eggs and sperm. Most commonly, some cells end up with one extra or missing chromosome (for a total of 45 or 47 chromosomes per cell), while other cells have the usual 46 chromosomes. Mosaic Turner syndrome is one example of chromosomal mosaicism. In females with this condition, some cells have 45 chromosomes because they are missing one copy of the X chromosome, while other cells have the usual number of chromosomes.

Many cancer cells also have changes in their number of chromosomes. These changes are not inherited; they occur in somatic cells (cells other than eggs or sperm) during the formation or progression of a cancerous tumor.

Can a change in the number of genes affect health and development?

2010-04-05T06:33:00.000-07:00

People have two copies of most genes, one copy inherited from each parent. In some cases, however, the number of copies varies—meaning that a person can be born with one, three, or more copies of particular genes. Less commonly, one or more genes may be entirely missing. This type of genetic difference is known as copy number variation (CNV).

Copy number variation results from insertions, deletions, and duplications of large segments of DNA. These segments are big enough to include whole genes. Variation in gene copy number can influence the activity of genes and ultimately affect many body functions.

Researchers were surprised to learn that copy number variation accounts for a significant amount of genetic difference between people. More than 10 percent of human DNA appears to contain these differences in gene copy number. While much of this variation does not affect health or development, some differences likely influence a person’s risk of disease and response to certain drugs. Future research will focus on the consequences of copy number variation in different parts of the genome and study the contribution of these variations to many types of disease.

What kinds of gene mutations are possible?

2010-04-05T06:31:00.000-07:00

The DNA sequence of a gene can be altered in a number of ways. Gene mutations have varying effects on health, depending on where they occur and whether they alter the function of essential proteins. The types of mutations include:

Missense mutation
This type of mutation is a change in one DNA base pair that results in the substitution of one amino acid for another in the protein made by a gene.

Nonsense mutation
A nonsense mutation is also a change in one DNA base pair. Instead of substituting one amino acid for another, however, the altered DNA sequence prematurely signals the cell to stop building a protein. This type of mutation results in a shortened protein that may function improperly or not at all.

Insertion
An insertion changes the number of DNA bases in a gene by adding a piece of DNA. As a result, the protein made by the gene may not function properly.

Deletion
A deletion changes the number of DNA bases by removing a piece of DNA. Small deletions may remove one or a few base pairs within a gene, while larger deletions can remove an entire gene or several neighboring genes. The deleted DNA may alter the function of the resulting protein(s).

Duplication
A duplication consists of a piece of DNA that is abnormally copied one or more times. This type of mutation may alter the function of the resulting protein.

Frameshift mutation
This type of mutation occurs when the addition or loss of DNA bases changes a gene’s reading frame. A reading frame consists of groups of 3 bases that each code for one amino acid. A frameshift mutation shifts the grouping of these bases and changes the code for amino acids. The resulting protein is usually nonfunctional. Insertions, deletions, and duplications can all be frameshift mutations.

Repeat expansion
Nucleotide repeats are short DNA sequences that are repeated a number of times in a row. For example, a trinucleotide repeat is made up of 3-base-pair sequences, and a tetranucleotide repeat is made up of 4-base-pair sequences. A repeat expansion is a mutation that increases the number of times that the short DNA sequence is repeated. This type of mutation can cause the resulting protein to function improperly.

Do all gene mutations affect health and development?

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No; only a small percentage of mutations cause genetic disorders—most have no impact on health or development. For example, some mutations alter a gene’s DNA base sequence but do not change the function of the protein made by the gene.

Often, gene mutations that could cause a genetic disorder are repaired by certain enzymes before the gene is expressed (makes a protein). Each cell has a number of pathways through which enzymes recognize and repair mistakes in DNA. Because DNA can be damaged or mutated in many ways, DNA repair is an important process by which the body protects itself from disease.

A very small percentage of all mutations actually have a positive effect. These mutations lead to new versions of proteins that help an organism and its future generations better adapt to changes in their environment. For example, a beneficial mutation could result in a protein that protects the organism from a new strain of bacteria.

How can gene mutations affect health and development?

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To function correctly, each cell depends on thousands of proteins to do their jobs in the right places at the right times. Sometimes, gene mutations prevent one or more of these proteins from working properly. By changing a gene’s instructions for making a protein, a mutation can cause the protein to malfunction or to be missing entirely. When a mutation alters a protein that plays a critical role in the body, it can disrupt normal development or cause a medical condition. A condition caused by mutations in one or more genes is called a genetic disorder.

In some cases, gene mutations are so severe that they prevent an embryo from surviving until birth. These changes occur in genes that are essential for development, and often disrupt the development of an embryo in its earliest stages. Because these mutations have very serious effects, they are incompatible with life.

It is important to note that genes themselves do not cause disease—genetic disorders are caused by mutations that make a gene function improperly. For example, when people say that someone has “the cystic fibrosis gene,” they are usually referring to a mutated version of the CFTR gene, which causes the disease. All people, including those without cystic fibrosis, have a version of the CFTR gene.

What is a gene mutation and how do mutations occur?

2010-04-04T10:08:00.000-07:00

A gene mutation is a permanent change in the DNA sequence that makes up a gene. Mutations range in size from a single DNA building block (DNA base) to a large segment of a chromosome.

Gene mutations occur in two ways: they can be inherited from a parent or acquired during a person’s lifetime. Mutations that are passed from parent to child are called hereditary mutations or germline mutations (because they are present in the egg and sperm cells, which are also called germ cells). This type of mutation is present throughout a person’s life in virtually every cell in the body.

Mutations that occur only in an egg or sperm cell, or those that occur just after fertilization, are called new (de novo) mutations. De novo mutations may explain genetic disorders in which an affected child has a mutation in every cell, but has no family history of the disorder.

Acquired (or somatic) mutations occur in the DNA of individual cells at some time during a person’s life. These changes can be caused by environmental factors such as ultraviolet radiation from the sun, or can occur if a mistake is made as DNA copies itself during cell division. Acquired mutations in somatic cells (cells other than sperm and egg cells) cannot be passed on to the next generation.

Mutations may also occur in a single cell within an early embryo. As all the cells divide during growth and development, the individual will have some cells with the mutation and some cells without the genetic change. This situation is called mosaicism.

Some genetic changes are very rare; others are common in the population. Genetic changes that occur in more than 1 percent of the population are called polymorphisms. They are common enough to be considered a normal variation in the DNA. Polymorphisms are responsible for many of the normal differences between people such as eye color, hair color, and blood type. Although many polymorphisms have no negative effects on a person’s health, some of these variations may influence the risk of developing certain disorders.

Top 50 Websites for Healthcare

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Sites in this category and its subcategories ordered by popularity. We didn’t receive any compensation from any of the listed sites.

1. www.nih.gov

US Government department in charge of medical research.

2. www.webmd.com/

A health resources for consumers, physicians, nurses, and educators. Includes news, chat forums, health quizzes and consumer product updates.

From the site: WebMD provides valuable health information, tools for managing your health, and support to those who seek information. You can trust that our content is timely and credible. ... The WebMD content staff blends award-winning expertise in medicine, journalism, health communication and content creation to bring you the best health information possible. Our esteemed colleagues at MedicineNet.com are frequent contributors to WebMD and comprise our Medical Editorial Board.

3. www.walgreens.com

Drug store chain. Features online buying facilities, career opportunities, company news, and investor information.

From the site: Walgreens Distribution Centers have developed a reputation for doing just that! We hire diverse, enthusiastic leaders who work well with their teams, have a passion for excellence and strive for even higher levels of growth, profitability, innovation and customer service.

4. www.focusonwomenshealth.com

Features news, clinical trial and articles.

5. www.ncbi.nlm.nih.gov/pubmed/

A national resource for molecular biology information for the better understanding of molecular processes affecting human health and disease.

6. www.mayoclinic.com

Clinical experts provide current medical information and news on health topics.

From the site: Produced by a team of Web professionals and medical experts working side by side, MayoClinic.com gives users access to the experience and knowledge of the more than 3,400 physicians and scientists of Mayo Clinic.

7. health.yahoo.com

Medical dictionary, disease symptoms and treatments, resources for healthy living, and information on drugs and medicines.

8. www.drugs.com/

Drugs.com is the most popular, comprehensive and up-to-date source of drug information online. Providing free, accurate and independent advice on more than 24,000 prescription drugs, over-the-counter medicines & natural products.

From the site: About Drugs.com Links on Google Co-op close ... Get Drugs.com trusted information when you Search on Google Drugs.com has been assisting to Google improve search results and categorize our content when you're on Google.com. To use this new feature, simply subscribe to Drugs.com on Google " Co-op " and you'll get more accurate and trusted results - plus you'll able to find what you are looking for much more easily.

9. www.nlm.nih.gov/medlineplus/

Research affiliation: Association of Research Libraries.

10. www.mercola.com/

Great source of health articles, optimal wellness products, and free natural health newsletter of top medical news by Dr. Joseph Mercola

From the site: In 1997 I started my web site, Mercola.com, that is now the most visited natural health site in the world. By 2006 we had over 800,000 subscribers and over 5 million page views every month. I created this site with no outside investors or advertising.

11. www.medhelp.org/

Med Help provides patient medical information via our virtual medical center. Site includes: the largest patient medical library on the Net, Ask-The-Doctor Forums, medical news, and patient networking.

From the site: Founded in 1994 out of a shared need for better medical information and support, MedHelp is the pioneer in online health communities. The MedHelp site connects people with the leading medical experts and others who have similar experiences. Today, MedHelp empowers over 5.5 million people each month to take control over their health and find answers to their medical questions. MedHelp has over 14 years of accumulated information from doctors and other patients across hundreds of conditions.

12. www.medscape.com/

Features medical journal articles, images, case reports, medical news, free Medline, CME, and drug searching.

From the site: Medscape is a part of WebMD Health Professional Network that includes theHeart.org and eMedicine.com. Click here for investor information, corporate management and press releases related to WebMD. ... Medscape offers specialists, primary care physicians, and other health professionals the Web's most robust and integrated medical information and educational tools. After a simple, 1-time, free registration, Medscape automatically delivers you the specialty site that best fits your profile.

13. www.cvs.com

Online version of the retail chain. Prescriptions, health, personal care, and gift items available online. Also provides health news and information from WebMD.

From the site: CVS Caremark is the nation's premier integrated pharmacy services provider, combining one of the nation's leading pharmaceutical services companies with the country’s largest pharmacy chain. The company fills or manages more than one billion prescriptions per year, more than any other pharmacy services provider.

14. news.bbc.co.uk/2/hi/health/

United Kingdom and international news headlines. Contains video and audio webcasts, forums, and in-depth articles.

15. www.menshealth.com/

Provide's information and tips on fitness, health, career, relationships, nutrition, recipes, weight-loss and muscle building.

From the site: Cory is the principal at Richard H. Gettys Middle School, in Easley, South Carolina, so all of these kids are his responsibility. They're also his motivation for change. "I'm worried about my kids," says Cory. "Most of them don't seem to be engaged in health and fitness." Cory sees great potential for all his students, but he can't ignore a serious threat to their futures. And he accepts a measure of blame for that.

16. www.cdc.gov/

Mission is to promote health and quality of life by preventing and controlling disease, injury, and disability. Includes guidelines, articles and resources for consumers and health professionals.

From the site: WISEWOMAN (W ell-I ntegrated S creening and E valuation for WOM en A cross the N ation) program is located at the Centers for Disease Control and Prevention (CDC) in Atlanta, ... CDC's state–based National Breast and Cervical Cancer Early Detection Program (NBCCEDP) offers an established framework that provides the opportunity to target other chronic diseases among women, including heart disease, the leading cause of death among women. Women who are eligible for.

17. www.everydayhealth.com

Provides health information, resources, communities, tools and news for conditions, treatments, wellness, diet and nutrition.

From the site: The Everyday Health Editors editor@everydayhealth.com About Waterfront Media: Waterfront Media ( www.waterfrontmedia.com ) is the largest privately held online health company. With the Internet at the core of its publishing platform, Waterfront Media's network of sites connects America's best health experts with millions of people looking to improve their lives through personalized advice, unique interactive features, tools and online communities.

18. www.weightwatchers.com/

Weight Watcher's point system allows you to eat what you want and lose weight.

From the site: WeightWatchers.com Press see recent press releases press contacts advertising with Weight Watchers Learn about exciting advertising opportunities on WeightWatchers.com. read more affiliate program Earn money the easy way - join the WeightWatchers.com Affiliate program! Our program is FREE to join and easy to set up. read more corporate information Weight Watchers is a leading provider of weight-loss services. Learn more about our company. read more employment opportunities.

19. patents.uspto.gov/

United States Patent and Trademark Office's (USPTO) patent databases - includes AIDS patents.

20.www.kidshealth.org/

KidsHealth.org, created by the children s health and family experts of the Nemours Foundation, has 1000 s of jargon-free, up-to-date, and reliable features, movies, and illustrations on the health and emotional development of babies, children and adolescents.

From the site: KidsHealth is the largest and most-visited site on the Web providing doctor-approved health information about children from before birth through adolescence. Created by The Nemours Foundation's Center for Children's Health Media, the award-winning KidsHealth provides families with accurate, up-to-date, and jargon-free health information they can use. KidsHealth has been on the Web since 1995 — and has been accessed by about half a billion visitors.

21. www.ncbi.nlm.nih.gov/sites/entrez

A national resource for molecular biology information for the better understanding of molecular processes affecting human health and disease.

22. www.realage.com/

RealAge delivers diet and fitness tools, low fat recipes, health risk quizzes, nutrition and stress tips, and vitamin recommendations to help you stay true to a younger you.

From the site: Roizen, MD , is cofounder of RealAge and chairman of the RealAge Scientific Advisory Board. He is a Phi Beta Kappa graduate of Williams College and Alpha Omega Alpha graduate of the University of California, San Francisco, School of Medicine. He performed his residency in internal medicine at Harvard's Beth Israel Hospital and completed a tour of duty in the Public Health Service at the National Institutes of Health in the laboratory of Irv Kopin and Nobel Prize winner Julius Axelrod.

23. www.emedicinehealth.com/

Information for consumers on the symptoms and treatment of nearly every type of disease and health condition, first aid procedures for accidents and injuries, and physical and the emotional well-being that contribute to general wellness.

From the site: In May 2003, eMedicine launched a new consumer health site, eMedicineHealth.com . Current medical information is available in 80 plus Centers to include: First Aid and Emergencies , ... Subsequent revisions of professional or consumer articles may be provided by internal eMedicineHealth copy editing staff, the physician author, or a physician or PharmD member of the editorial board associated with each article.

24. www.aolhealth.com/

Find advice, information about diseases and drugs, fitness tips, and news items.

From the site: In addition to the relationships it may have with content providers, AOL may also accept other advertising and promotions from third parties ("AOL Body Advertisers"). Such advertising and promotions (including without limitation banner, badge and contextual advertising) contain information relating to specific products and information on health-related topics that is produced by or at the direction of the AOL Body Advertiser (“Advertisements”).

25. www.who.int/

From the site: Introductory brochure on WHO [pdf 1.24Mb] WHO is the directing and coordinating authority for health within the United Nations system. It is responsible for providing leadership on global health matters, shaping the health research agenda, setting norms and standards, articulating evidence-based policy options, providing technical support to countries and monitoring and assessing health trends.

26. www.nhs.uk

From the site: NHS Choices puts you in control of your healthcare. This website has been developed to help you make choices about your health, from lifestyle decisions about things like smoking, drinking and exercise, through to the practical aspects of finding and using NHS services when you need them. It draws together the knowledge and expertise of: the National Library for Health, NHS Direct, the Information Centre for Health and Social Care, the Healthcare Commission and many other organisations.

27. www.prevention.com/

Information about getting fit, losing weight, and living healthier lives from Prevention.com.

From the site: Prevention is the #1 healthy lifestyle magazine brand and the 10th largest magazine in the nation, with more than 11 million readers. The top online health magazine destination, Prevention.com has 1.6 million unique visitors each month. Prevention publishes branded books, special-interest publications, international editions, bookazines, and DVDs under the bestselling Prevention Fitness Systems as well as leads Team Prevention walking programs at marathons across the country.

28. www.rxlist.com/

Searchable cross index of US prescription products providing links to full prescribing information as well as patient education material.

From the site: RxList.com - Owned and Operated by WebMD and part of the WebMD network. RxList is an online medical resource dedicated to offering detailed and current pharmaceutical information on brand and generic drugs. Founded by pharmacists in 1995, RxList is the premier Internet Drug Index resource.

29. www.healthline.com/

Healthline is the first Internet search engine dedicated to consumer healthcare. Healthline’s unique HealthMaps® enable users to visually explore all of the information related to a disease, drug or condition without the need to repeatedly type new queries into the search box, and the site s Medically Guided Search tools make it easier for users to find comprehensive healthcare information from over 62,000 health and medicine websites.

From the site: Healthline Networks offers the easiest way for consumers to quickly and easily find consistently excellent health information on the Web. By utilizing its robust search and navigation platform, Healthline is focused on becoming the global leader in intelligent health information services, enabling consumers to make more confident, informed decisions about their health.

30. www.health.com

Monthly articles from the print magazine.

From the site: Health is America’s most-trusted health and wellness magazine, giving women the most credible, useful, and up-to-date information and inspiration on how to live a healthier, happier life. Its get-real perspective helps readers make sense of conflicting news, trends, and studies. Health covers well-being, fitness, nutrition, and beauty with intelligence and flair, showing that healthy living truly looks good on you.

31. www.stevepavlina.com

Free personal development and conscious living resources, with a focus on discovering your life purpose and summoning the courage to begin acting on it.

From the site: Steve Pavlina is widely recognized as one of the most successful personal development bloggers on the Internet, attracting more than two million monthly readers to his website, StevePavlina.com. He has written more than 700 articles and recorded many audio programs on a broad range of self-help topics, including productivity, relationships, and spirituality. Steve has been quoted as an expert by the New York Times , USA Today , U.S.

32. www.netdoctor.co.uk/

Extensive collection of health information for paients, provided by an independent commercial company with a team of medical editors.

From the site: NetDoctor.co.uk is committed to helping both parties in their quest. NetDoctor.co.uk is a collaboration between committed doctors, health care professionals, information specialists and patients who believe that medical practice should be based on quality-assessed information and, wherever possible, on the basis of the principles of evidence-based medicine. Over 250 of the UK's and Europe's leading doctors and health professionals write, edit and update the contents of NetDoctor.co.uk.

33. www.healthcentral.com

Timely, in-depth, trusted medical information, personalized tools and resources, and connections to a vast community of leading experts and patients for people seeking to manage and improve their health.

From the site: Content provided by HealthCentral.com and Euflexxa™ Understanding OA of the Knee provided by Euflexxa Causes of OA of the Knee provided by Euflexxa.

34. www.psychologytoday.com/

Featured columns on relationships, mental health education, and work related issues. Recent mental health news and archives. Includes a national therapist directory.

From the site: Our staff of writers, editors and programmers include individuals who have extensive expertise in the field of psychology, both from a clinical and an academic perspective. Many of our articles are written by, and rely upon information provided by, Doctors and Ph.D.'s who have dedicated their professional lives to the promotion of sound psychology for the benefit of the communities in which they live.

35. www.healthboards.com/

A moderated wide variety of health related message boards includes cancer, allergies, alternative health, mental health, cerebal palsy, disabilities, lupus, and others.

From the site: HealthBoards.com is a place where you can make those connections. HealthBoards provides a unique one-stop support group community offering over 150 message boards on various diseases, conditions, and health topics. The HealthBoards community is one of the largest and most dynamic on the Web, with over 400,000 registered members, and over 3 million messages posted.

36. www.fda.gov

The Consumer Protection Agency of the U.S. Government which monitors medical devices, foods, drugs, biologics, veterinary medicine, and toxicological research.

From the site: MedWatch -- FDA provides safety information on drugs and other FDA-regulated products, and allows for adverse event reporting. Recalls -- FDA posts significant product actions of the last 60 days. Inspections - FDA inspects processing plants and other agency-regulated facilities. ... FDA convenes public meetings with outside experts for advice on making key public health decisions. ... Does FDA control pesticides in foods? How can I participate in FDA's process for making its rules?

37. www.bmj.com/

Electronic version of the BMJ. Publish accessible information that will help doctors improve their practice and will influence the international debate on health. Access is free to all.

38. www.medicalnewstoday.com

One of the major online medical/health news journals. Updated hourly, with between 150 and 220 articles posted per day from the world s leading universities and research institutions. Medical News Today also offers free access to its news archive of over 100,000 articles.

From the site: More than 2 million unique visitors come to medicalnewstoday.com every month. Sister sites include www.medilexicon.com - the most popular medical abbreviation search facility on the Internet - and www.hospitalsworldwide.com - a searchable database of hospitals throughout the world. The 3 websites attract more than 3 million unique visitors every month.

39. www.emedtv.com/

A library of medical information including conditions and diseases, tests and procedures and drugs and supplements.

From the site: Use eMedTV's tools for health and fun including our BMI calculator, baby names builder, and more. ... The eMedTV Web site was developed and is owned by Clinaero, Inc. Clinaero is a privately held software and services company focused in two areas – clinical trials and health information. ... Through eMedTV, Clinaero is committed to providing accurate and credible health information to our users, both in written and multimedia format.

40.familydoctor.org/

Health information for the whole family from the American Academy of Family Physicians.

From the site: Gracias por visitar nuestro sitio familydoctor.org . ... Si tiene una emergencia médica y está en territorio estadounidense, por favor marque 911. familydoctor.org.

41. www.socialsecurity.gov/

Official site, with news, trends, budget, publications, and comparison with systems in more than 170 countries.

From the site: Service is available by telephone, mail, in person at an office, or electronically through the Internet at: http://www.socialsecurity.gov/reach.htm . The toll–free number is 1–800–772–1213 . Service representatives are on duty to answer your calls between 7 a.m. and 7 p.m., on business days. Recorded information and services are available 24 hours a day and on weekends. Spanish speaking representatives are available to speak with callers who prefer to do business with us in Spanish.

42.www.riteaid.com

Online refills, store locator, many specials and health care information. Rite Aid serves millions of customers each day in over 4,000 neighborhood locations that extend to 30 states on both the East and West Coasts and in the District of Columbia. Based in Camp Hill, PA.

From the site: If you have questions, ask your pharmacist or call 1-800-RITEAID.

43. www.makeupalley.com/

A hip beauty community and social network featuring interactive member generated content including beauty product reviews, messageboards, shopping diaries and much more.

44. www.24hourfitness.com/

Centers and health club locations worldwide, personal training, exercise classes.

From the site: Over the past 25 years, 24 Hour Fitness has built or opened more clubs in the United States than any other privately-owned fitness club chain. The company is widely credited with changing the industry landscape by introducing a variety of innovations, including extended hours and month-to-month memberships. In 2004, 24 Hour Fitness became the first official fitness center sponsor of the United States Olympic team. The sponsorship grants memberships to selected U.S.

45. www.wellness.com

Includes health resources, discussion and news.

From the site: Learn, Comment & Contribute on Wellness.com ... Wellness.com's mission is to help millions of people live healthier, happier lives. Wellness.com is the place to learn more about achieving health and happiness while meeting like-minded people, new friends, and experts who can enhance our lives. It is widely accepted that wellness (optimal balanced health & happiness) cannot be bought or acquired passively.

46.www.telegraph.co.uk/health/index.jhtml

International online news from the United Kingdom paper.

From the site: How to use telegraph.co.uk - FAQ ... General Information telegraph.co.uk telegraph.co.uk was created in November 1994, establishing the Telegraph as the first online daily UK newspaper in the UK. Extensive developments in recent months include the creation of Telegraph IQ , an interactive quiz, film site , music downloads and video streaming, a personal finance product comparison service, theatre, music event and gallery bookings.

47. pregnancy.about.com/

A week by week calendar, prenatal testing information, breastfeeding, labor, signs and symptoms.

48. www.apa.org/

Promotes research and represents the professional interests of psychologists in the United States. Includes information on publications and conferences, and a find-a-psychologist referral feature.

From the site: The APA Public Interest Directorate supports and promotes efforts to apply the science and profession of psychology to the advancement of human welfare. Public Interest issues are of central importance to the science and profession of psychology and critical to consumers of psychological services and the general public.

49. www.home-remedies-for-you.com/

Information on causes, symptoms and diet conditions for common ailments and diseases. Also provides information on health benefits from common ingredients like honey, garlic, aloe vera and other items.

From the site: Terms and Conditions for Usage of this Site www.home-remedies-for-you.com does not provide medical advice, diagnosis or treatment.

50.www.revolutionhealth.com/

Provides advice and guidance to help individuals manage their health care, with product comparisons, membership plans, and an online store.

From the site: RevolutionHealth.com: The cornerstone of Revolution Health is RevolutionHealth.com, a free, comprehensive health and medical information site, specifically designed with the Family's Chief Medical Officer — women and other caregivers — in mind.RevolutionHealth.com offers best-of-breed health information as well as more than 125 online tools aimed at helping individuals take control of their well-being.

Scientists describe 'secret of life' in 1953

2010-04-03T07:38:00.000-07:00

Two Cambridge University scientists have published their answer to one of the most fundamental questions of biology - how do living things reproduce themselves?

X-ray diffraction photos of DNA helped to solve the puzzle of reproduction
Courtesy: King's College London

In an article published today in Nature magazine, James D Watson and Francis Crick describe the structure of a chemical called deoxyribonucleic acid, or DNA.

DNA is the material that makes up genes which pass hereditary characteristics from one parent to another.

In short, it consists of a double helix of two strands coiled around each other. The strands are made up of complementary elements that fit together and when uncoiled can produce two copies of the original.

Momentous discovery

This special property for accurate self-replication allows DNA to duplicate the genes of an organism during the nuclear divisions for growth and the production of germ cells for the next generation.

They began their article with the modest statement: "We wish to suggest a structure for the salt of deoxyribose nucleic acid (DNA). This structure has novel features which are of considerable biological interest."

On 28 February, Mr Crick walked into a Cambridge pub with Mr Watson to celebrate the fact that they had unravelled the structure of DNA, saying: "We have discovered the secret of life!"

The momentous discovery was the culmination of research by Medical Research Council scientists Maurice Wilkins and Rosalind Franklin in London, who produced X-ray diffraction photographs and other evidence.

Bioethics: Human-animal hybrid embryos

2010-04-03T07:30:00.003-07:00

Human stem cells

In May 2008 a cross-party attempt to ban hybrid human animal embryos was defeated on a free vote in the House of Commons, by 336 to 176. MPs had been debating the Human Fertilisation and Embryology Bill, which would allow regulated research using hybrid or 'admix' embryos, where the nuclei of human cells are inserted into animal eggs. The resulting embryos would be kept for up to 14 days to harvest stem cells.

In the present state of science, hybrid embryos are produced as research tools, and only kept alive for 14 days or fewer. The article below only deals with the ethical issues of this case, and not with the ethics of producing new creatures that are a combination of animal and human.

A hybrid embryo is a mixture of both human and animal tissue. There are several types of hybrid embryo (listed below), but recent controversy has focused on cytoplasmic embryos.

These are created by transferring nuclei containing DNA from human cells into animal eggs that have had almost all of their genetic information removed.

The resulting embryos are more than 99% human, with a small animal component, making up around 0.1% (more detail below).

The embryos are grown in the lab for a few days, then harvested for stem cells: immature cells that can become many types of tissue. The embryonic stem cells are used in research into different diseases as a way of addressing the shortage of human eggs available for research.

Scientists do not intend to actually create living animal-human hybrids. [Such beings are often referred to as chimeras after a creature in Greek mythology which had a lion's head, a goat's body, and a serpent's tail.]

Some 200 medical charities have urged MPs to support legislation allowing the creation of animal-human embryos.

Possible types of animal/human hybrid embryos

Cytoplasmic hybrid embryos: embryos created through cell nuclear replacement using animal eggs
Hybrid embryos: embryos created by mixing human sperm and animal eggs or human eggs and animal sperm
Human chimera embryos: human embryos which have animal cells added to them during early development
Animal chimera embryos: animal embryos which have human cells added to them during early development
Transgenic human embryos: human embryos which have animal genes inserted into them during early development

Source: Human Fertilisation and Embryology Authority

Proportions of human and animal DNA

In cytoplasmic hybrid embryos, all the DNA in the cell nucleus is human. The remaining animal DNA is found only in the mitochondria, which are small rod-shaped organelles found outside the nucleus that produce energy for the cell. Mitochondrial DNA is separate from nuclear DNA; it is not involved in cellular division or reproduction.

So the main genetic material is 100% human. Embryos produced by this technique are considered fully human - a "live human embryo" - by the Human Fertilisation and Embryology Act.

A combination of human nuclear DNA and animal mitochondria is likely to make a difference to the resulting cells, but not enough is known about mitochondrial disorders to predict what the effects might be. The House of Commons Select Committee report acknowledged this and viewed it as a positive point.

However, rather than deem this a reason not to conduct such research, [Dr Justin St John from Birmingham University] believes that the creation of human-animal chimera or hybrid embryos may actually "offer us the opportunity to elucidate some of the causes of mitochondrial DNA disease" and that "not to allow this work to go ahead would considerably disadvantage experimental work in these fields".

House of Commons Select Committee on Science and Technology Fifth Report, June 2007

Public opinion

In 2007, a poll conducted by the HFEA found that 61% of the public supported the research after having the process and goals explained to them, while a quarter was opposed to the research.

The debate

Ethical issues

We believe, too, that we are God's partners in the work of creation, both as innovators and as protectors, and that this partnership obliges us to be guided by ethical principles.

Office of the Chief Rabbi, Memorandum to Select Committee on Science and Technology November 2004

There are strong arguments on both sides of the ethics of creating human/animal embryos. We've listed some of the arguments put forward below.

In some cases the arguments seem to be similar but expressed in a different way.

In some cases arguments on the same side of the case seem to conflict with each other.

Quotations on both sides of the argument can be found at BBC News - In quotes: The ethics of embryos

Arguments against creating human/animal embryos

...the creation of an animal-human being represents a natural border that has been violated, the most grave of violations.

Bishop Elio Sgreccia, president of Pontifical Academy for Life, May 2007

It blurs the distinction between human beings and other animals
It's a repulsive thing to do
It's unnatural
It's playing God
It violates human dignity
Human embryos have a special (moral) status from the moment of fertilisation that should be respected and this makes any research using human embryos wrong and a violation of their human rights
It's wrong to create beings (embryos) that are solely at the disposal of scientists; it says that it is acceptable to create motherless beings and could open the way to the creation of beings that are effectively owned by whoever controls the medium in which the embryo develops
Even if using human embryos for research is sometimes acceptable, creating animal/human hybrid embryos is a step too far
It's the start of a slippery slope that could lead to creating hybrid human/animal creatures capable of independent life
It's wrong to use animals in this sort of research
The research will be of little scientific value - no new treatments have been produced by embryonic stem cell research
Mixing human and animal genetic material risks creating new diseases

Arguments in favour of creating human/animal embryos

We think there is nothing illegal, immoral or unethical about this.

While we understand the concerns, we think they are largely founded on misinformation. People think we are generating some sort of hybrid animal. This is just cells, just for science. No animal is ever going to be created.

Professor Chris Shaw, Kings College London, 2008

It may produce enormous benefits for human beings
It is a strictly limited procedure - creatures capable of independent life will not be created. These are 'just cells', not actual beings
It avoids the use of human eggs in research
The genetic contribution of the animal to the embryo is so small that it is essentially a human embryo
Since the embryo was not produced by human fertilisation, it can't be regarded as a human embryo
It's very similar to cell nuclear replacement research, and if we accept research on human embryos up to 14 days, there is no reason to oppose research on an embryo that is less than wholly human
Neither human nor animal rights are violated since the embryo will never be allowed to become a human or an animal

(source: BBC Science)

Genes not to be patented: U.S. judge

2010-03-31T06:28:00.000-07:00

A judge in U.S. Federal District Court in Manhattan ruled that two breast and ovarian cancer related genes were not to be patented since they are nature's products, reports said Wednesday.

Seven patents on the genes held by Myriad Genetics of Utah were not valid, the judge Robert W. Sweet declared.

Over the past two decades, academic researchers and private companies have claimed patents on more than 4,300 human genes.

With patents of BRCA1 and BRCA2, two genes associated with breast and ovarian cancer, Myriad allowed researchers to test anonymous specimens.

However, if individuals sought to know if they carried the mutations that raised risks for breast and ovarian cancer, Myriad insisted that only its labs test them, at a cost of 3,000 dollars, according to Dr. Harry Ostrer, director of molecular genetics at NYU Langone Medical Center.

In Canada, where the patent is not honored, the test is available for under 1,000 dollars, Judge Sweet noted.

In 2009, patients, doctors and an association of pathologists sued to challenge the Myriad patents.

Dr. Ostrer, a plaintiffs, said that patients needed more than the Myriad test to inform them of their risks, because it identifies only the BRCA1 and BRCA2 genes, but a number of other genes are also associated with a risk for cancer.

The case was brought by the American Civil Liberties Union and the Public Patent Foundation at the Benjamin N. Cardozo School of Law.

Myriad defended itself by claiming the patents allowed its investors to make their money back. Moreover, it argued, by isolating the genes in the laboratory, it had created chemicals that did not exist in nature -- a critical test for patents.

Judge Sweet rejected that argument, deciding that a gene is a gene, whether it is inside a human cell or in a test tube.

(Agencies)

• Gene linked to lung cancer risk in non-smokers

• Genes test may guide dieting

• Genes may be linked with preterm births: U.S. researchers

• Gene map for malaria crop offers higher yield hope

• Austrian scientists to curb obesity by using gene

Scientists make genetically-modified cow with high Omega-3 fatty acid level

2010-03-27T17:54:00.002-07:00

The world's first genetically-modified cow with high level of Omega-3 fatty acid is nine-months old, healthy and expected to produce milk rich in the fatty acid essential for human health, Chinese scientists said Friday.

Li Guangpeng, chief of the program, said two embryo-cloned and genetically-modified dairy cows were born on June 23 last year. One of the cows has been found to have an Omega-3 fatty acid level 10 times higher than a normal cow.

"We did not announce the birth of the clone cows until now because it has taken time to check the cows' effective genetic traces," said Li, head of the Biological Technology Lab at Inner Mongolia University.

Li said it takes 14-15 months for a cow to become sexually mature, and another nine months to produce milk.

"We expect the cow to be able to produce milk with high Omega-3 content next year," he said.

He said the cows have been fed with normal cow feed.

Dubbed a "good fat", Omega-3 is an essential fatty acid necessary for human health. But it cannot be made by the human body. It is abundant in walnuts and coldwater fish like herring, mackerel and sturgeon.

"Another two cloned cows with the 'fish oil' gene were born on Tuesday. It will take time to see whether they are healthy," Li said.

Li said the program involved a team of experts from China and the United States, including the Chinese Academy of Sciences' Lai Liangxue and the University of Pittsburgh's Yifan Dai.

DNA from Sebria may signal new species of human ancestor

2010-03-27T17:54:00.001-07:00

BEIJING, March 27-- Scientists used a DNA-decoded method to investigate an ancient human who has been discovered in a cave in southern Siberia, according to British newspaper Daily Mail.

Living 6.8million years ago this is Sahelanthropus tchadensis. Parts of its jaw bone and teeth were found nine years ago in the Djurab desert, Chad, and from this scientists created this model head.(Photo Source:CRIOnline.com)

The mysterious human, who lived alongside our ancestors tens of thousands of years ago, earned a nickname “X-Woman”.

Through analysing DNA from a fossilized finger bone, researchers found it doesn't match modern humans or Neanderthals, two species that lived in that area around the same time - 30,000 to 50,000 years ago.

The Siberian species lineage may split off from the branch leading to moderns and Neanderthals a million years ago, the researchers calculated.

And they also said that it doesn't seem to match the history of human ancestors previously known from fossils.

Researchers presumed that the Siberian species may be brand new, although they cautioned that they're not ready to make that claim yet.

This paleoanthropological breakthrough may rewrite mankind's family tree.

(Agencies)

US Scientists Unlock Clues to Mystery of Butterfly Migration

2010-03-23T06:58:00.000-07:00

Researchers find circadian clock in Monarch's antenna plays a major role in navigation

Shelley Schlender | Michoacán, Mexico 22 March 2010

Photo: USFWS

Scientists believe antennas are critical to the navigation of the Monarch butterfly.

Biomedical Videos

2010-01-04T07:31:00.000-08:00

Free Biology Videos and Movies

This lecture by Dr. Nadia Rosenthal discusses the importance of adult stem cells in the tissue maintenance, development and regeneration. Part 3 of 6. HHMI description: Mature organisms have stem cells of various sorts, called adult stem cells. Adult stem cells supply cells that compensate for the loss of cells from normal cell death and turnover, such as the ever-dying cells of our skin, our blood, and the lining of our gut. They are also an essential source of cells for healing and regeneration in response to injury. Some animals, such as sea stars, newts, and flatworms, are capable of dramatic feats of regeneration, producing replacement limbs, eyes, or most of a body. It is an evolutionary puzzle why mammals have more limited powers of regeneration. Researchers are interested in pinpointing where adult stem cells reside and in understanding how flexible adult stem cells are in their ability to produce divergent cells such as muscle and red blood cells. Understanding the sources and the rules for the differentiation of adult stem cells is essential for tapping their therapeutic potential. Since consenting adults can provide adult stem cells, some people think that adult stem cells may be a less controversial area of Research than embryonic stem cells.Date: 2008-09-03 23:50:28 - Added by: ebiotek

	Animal Cloning
	Animal cloning gone bad, waaaay bad Check out our website: www.KnGproduction.com
	Date: 2008-09-03 23:58:32 - Added by: ebiotek


	How to Clone a Sheep
	If you\'ve ever wondered how to clone a sheep, this simple step-by-step demonstration is just what you\'ve been looking for. Ten simple steps is all it takes to go from egg cell to infant sheep clone. DO NOT ATTEMPT AT HOME.
	Date: 2008-09-03 23:57:25 - Added by: ebiotek


	Cloning
	cloning video i made for class my junior year of high school
	Date: 2008-09-03 23:56:41 - Added by: ebiotek


	biology - nuclear transfer (clone creating)
	Nuclear Transfer is a form of cloning. The steps involve removing the DNA from an oocyte and while(unfertilized egg), and injecting the nucleus which contains the DNA to be cloned. In rare instances, the newly constructed cell will divide normally, replicating the new DNA while remaining in a pluripotent state. If the cloned cells are placed in the uterus of a female mammal, a cloned organism develops to term in rare instances. This is how Dolly the Sheep and many other species were cloned. Alternatively, if cells are extracted from the cloned cells during very early embryonic stages (blastocyst or morula), embryonic stem cells can be created. These cells can be grown in laboratories indefinitely and can theoretically be made into any of the 200+ cell types in the mammalian body, and thus are an extraordinary tool for biologists as well as a therapeutic agent with the potential to treat currently untreatable medical conditions.
	Date: 2008-09-03 23:55:55 - Added by: ebiotek


	Stem Cells and Human Cloning
	Dr Andrew Corbett presents the Stem Cell and Human Cloning Debate from an ethical perspective...
	Date: 2008-09-03 23:55:27 - Added by: ebiotek


	What's the difference between embyonic and adult stem cells?
	A 10 minute discussion on the difference between embryonic and adult stem cells. Focus is on the use of mesenchymal stem cells.
	Date: 2008-09-03 23:54:29 - Added by: ebiotek


	Adult Stem Cells and Regeneration Part 3 of 6




	Adult Stem Cells and Regeneration Part 2 of 6
	This lecture by Dr. Nadia Rosenthal discusses the importance of adult stem cells in the tissue maintenance, development and regeneration. Part 2 of 6. HHMI description: Mature organisms have stem cells of various sorts, called adult stem cells. Adult stem cells supply cells that compensate for the loss of cells from normal cell death and turnover, such as the ever-dying cells of our skin, our blood, and the lining of our gut. They are also an essential source of cells for healing and regeneration in response to injury. Some animals, such as sea stars, newts, and flatworms, are capable of dramatic feats of regeneration, producing replacement limbs, eyes, or most of a body. It is an evolutionary puzzle why mammals have more limited powers of regeneration. Researchers are interested in pinpointing where adult stem cells reside and in understanding how flexible adult stem cells are in their ability to produce divergent cells such as muscle and red blood cells. Understanding the sources and the rules for the differentiation of adult stem cells is essential for tapping their therapeutic potential. Since consenting adults can provide adult stem cells, some people think that adult stem cells may be a less controversial area of research than embryonic stem cells.
	Date: 2008-09-03 23:50:10 - Added by: ebiotek


	Adult Stem Cells and Regeneration Part 1 of 6
	This lecture by Dr. Nadia Rosenthal discusses the importance of adult stem cells in the tissue maintenance, development and regeneration. Part 1 of 6. HHMI description: Mature organisms have stem cells of various sorts, called adult stem cells. Adult stem cells supply cells that compensate for the loss of cells from normal cell death and turnover, such as the ever-dying cells of our skin, our blood, and the lining of our gut. They are also an essential source of cells for healing and regeneration in response to injury. Some animals, such as sea stars, newts, and flatworms, are capable of dramatic feats of regeneration, producing replacement limbs, eyes, or most of a body. It is an evolutionary puzzle why mammals have more limited powers of regeneration. Researchers are interested in pinpointing where adult stem cells reside and in understanding how flexible adult stem cells are in their ability to produce divergent cells such as muscle and red blood cells. Understanding the sources and the rules for the differentiation of adult stem cells is essential for tapping their therapeutic potential. Since consenting adults can provide adult stem cells, some people think that adult stem cells may be a less controversial area of research than embryonic stem cells.
	Date: 2008-09-03 23:49:50 - Added by: ebiotek


	Adult Stem Cells and Regeneration Part 6 of 6
	This lecture by Dr. Nadia Rosenthal discusses the importance of adult stem cells in the tissue maintenance, development and regeneration. Part 6 of 6. HHMI description: Mature organisms have stem cells of various sorts, called adult stem cells. Adult stem cells supply cells that compensate for the loss of cells from normal cell death and turnover, such as the ever-dying cells of our skin, our blood, and the lining of our gut. They are also an essential source of cells for healing and regeneration in response to injury. Some animals, such as sea stars, newts, and flatworms, are capable of dramatic feats of regeneration, producing replacement limbs, eyes, or most of a body. It is an evolutionary puzzle why mammals have more limited powers of regeneration. Researchers are interested in pinpointing where adult stem cells reside and in understanding how flexible adult stem cells are in their ability to produce divergent cells such as muscle and red blood cells. Understanding the sources and the rules for the differentiation of adult stem cells is essential for tapping their therapeutic potential. Since consenting adults can provide adult stem cells, some people think that adult stem cells may be a less controversial area of research than embryonic stem cells.
	Date: 2008-09-03 23:49:20 - Added by: ebiotek

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Genetics and Birth Defects (Source:NIH)

2009-12-20T03:37:00.000-08:00

Abnormalities see Birth Defects

Achondroplasia see Dwarfism

Acid Maltase Deficiency see Metabolic Disorders

Adrenoleukodystrophy see Leukodystrophies

Alpha-1 Antitrypsin Deficiency

Anencephaly see Neural Tube Defects

Arnold-Chiari Malformation see Head and Brain Malformations

Birth Defects

Brain Malformations see Head and Brain Malformations

Canavan Disease see Leukodystrophies

Cerebral Palsy

Charcot-Marie-Tooth Disease

Cleft Lip and Palate

Congenital Heart Disease

Cystic Fibrosis

Dandy-Walker Syndrome see Head and Brain Malformations

Down Syndrome

Duchenne Muscular Dystrophy see Muscular Dystrophy

Dwarfism

Ehlers-Danlos Syndrome

Family History

Fetal Alcohol Syndrome

Fragile X Syndrome see Genetic Disorders

Gaucher's Disease

Genes

Genetic Brain Disorders

Genetic Disorders

Genetic Testing/Counseling

Head and Brain Malformations

Hemochromatosis

Hemophilia

Human Genome Project see Genes

Huntington's Disease

Hydrocephalus

Hypermobility Syndrome see Ehlers-Danlos Syndrome

Mucopolysaccharidoses see Metabolic Disorders

Muscular Dystrophy

Neural Tube Defects

Neurofibromatosis

Osteogenesis Imperfecta

Personalized Medicine

Phenylketonuria

PKU see Phenylketonuria

Prader-Willi Syndrome

Rare Diseases

Sickle Cell Anemia

Spina Bifida

Spinal Muscular Atrophy

von Recklinghausen's Disease see Neurofibromatosis

Wilson's Disease

Diseases and Genes

2009-12-20T03:08:00.001-08:00

Introduction to Genes and Disease

(source:NIH)

Genes and Disease is a collection of articles that discuss genes and the diseases that they cause. These genetic disorders are organized by the parts of the body that they affect. As some diseases affect various body systems, they appear in more than one chapter.

With each genetic disorder, the underlying mutation(s) is discussed, along with clinical features and links to key websites. You can browse through the articles online, and you can also download a printable file (PDF) of each chapter.

From Genes and Disease you can delve into many online related resources with free and full access. For example, you can visit the human genome to see the location of the genes implicated in each disorder. You can also find related gene sequences in different organisms. And for the very latest information, you can search for complete research articles, and look in other books in the NCBI Bookshelf. Currently over 80 genetic disorders have been summarized, and the content of Genes and Disease is continually growing.

The sequence of the human genome is providing us with the first holistic view of our genetic heritage. While not yet complete, continued refinement of the data bring us ever closer to a complete human genome reference sequence. This will be a fundamental resource in future biomedical research.

The 46 human chromosomes (22 pairs of autosomal chromosomes and 2 sex chromosomes) between them house almost 3 billion base pairs of DNA that contains about 30,000 - 40,000 protein-coding genes. The coding regions make up less than 5% of the genome (the function of the remaining DNA is not clear) and some chromosomes have a higher density of genes than others.

Most of the genetic disorders featured on this web site are the direct result of a mutation in one gene. However, one of the most difficult problems ahead is to find out how genes contribute to diseases that have a complex pattern of inheritance, such as in the cases of diabetes, asthma, cancer and mental illness. In all these cases, no one gene has the yes/no power to say whether a person has a disease or not. It is likely that more than one mutation is required before the disease is manifest, and a number of genes may each make a subtle contribution to a person's susceptibility to a disease; genes may also affect how a person reacts to environmental factors. Unraveling these networks of events will undoubtedly be a challenge for some time to come, and will be amply assisted by the availability of the sequence of the human genome.

Scientists Crack Genetic Code of Two Common Cancers

2009-12-19T01:07:00.001-08:00

Discovery could revolutionize cancer care, saving millions of lives

Carol Pearson | Washington 19 December 2009

It is being called a scientific breakthrough. British researchers say they have mapped the entire genetic code for two types of cancers -- small cell lung cancer and melanoma, the most deadly type of skin cancer.

All cancers are caused by changes in the DNA of cells. DNA carries the cells' genetic information. That information changes when cells gradually mutate from normal to abnormal and then to malignant over time.

Scientists say if they could only crack the genetic codes of different types of cancers, they could save millions of lives.

Blood tests could spot tumors early on. And treatment would be far more successful. Dr. Jeanny Aragon-Ching is an oncologist at the George Washington University Medical Center. She says this discovery is a step toward an era of personalized medicine. "That is the thrust now because, for instance, for different types of cancers, we have different types of drugs that target different domains or mutations," she said.

The more information doctors have about how cancer cells develop, the more precisely they can prescribe a treatment to target those particular cells.

British scientists found 30,000 mutations in melanoma, a type of skin cancer that accounts for 75 percent of skin cancer deaths. They also found 23,000 mutations in small cell lung cancer. But not all of these mutations cause cancer. "It is the role of physicians and scientists to find out which of those mutations are the driving force, or the driving mutation that actually led to the cancer," she said.

Eventually, scientists might be able to target pre-cancerous cells and prevent deadly tumors from forming. But that day is still far away. "As an oncologist, my goal would be to one day see that we can transform cancer into a chronic disease. Cure is probably too generous of a word the way I see it, but to convert it to something more like chronic disease that is treatable," she said.

Just like high blood pressure that can be controlled with medicine, cancer could be a disease without the suffering we associate with it. Medical scientists the world over are now working to catalogue all the genes that mutate in many types of cancer as part of an International Cancer Genome Consortium. In the United States they are studying cancers of the brain, ovaries and pancreas.

In addition to lung cancer and melanoma, scientists are examining the DNA of breast cancer, as well as cancers of the liver, the mouth and the stomach. "I think each step forward is a step toward our goal, our ultimate goal, which is to relieve the suffering from cancer," she said.

Scientists Discover New Species of Dinosaur

2009-12-15T00:32:00.001-08:00

Paleontologists say the dinosaur they call Tawa, was about the size of a large dog, but with a longer tail.

Jessica Berman | Washington , from VOA

Scientists have discovered the fossilized remains of a new meat-eating dinosaur in a quarry in New Mexico. They say the finding sheds light on the evolution of these extinct creatures.

Paleontologists say the dinosaur they call Tawa, named for the Hopi Native American sun god, was about the size of a large dog, but with a longer tail, stood about 70 centimeters tall at the hips and was two meters long. The two-legged creature also had razor-sharp teeth for eating meat.

Scientists conducting an analysis of the newly-discovered, 215 million year old fossils and other early dinosaur remains say Tawa also had the characteristics of two other dinosaurs - the giant, plant-eating sauropod and the horned Triceratops.

They believe Tawa is the common ancestor of both dinosaur groups that migrated from Argentina to other parts of the world during the Pangea period, between 200 and 300 million years ago, when geologists say the Earth's continents were compressed into a single landmass.

The fossil discovery suggests that Tawa also used a land bridge from South America to make its way to North America, when Tyrannosaurus Rex began evolving into modern day birds, according to Sterling Nesbitt, a researcher at the University of Texas who led a team of excavators.

"Tawa is a little bit of a surprise because it's preserving these very early traits that we see in dinosaurs while living with animals that are much more closely related to bird," said Nesbitt.

According to Nesbitt, Tawa might answer important questions about a dinosaur called Herrerasaurus, which was discovered in Argentina in the 1960s.

Herrerasaurus has traits like T. Rex - including sharp claws and teeth - but lacks other characteristics of the carnivore. Scientists hope to determine whether Herrerasaurus is a direct descendant of Tawa or part of a different species of dinosaurs.

Nesbitt say the Hayden Quarry in northern New Mexico, where the ancient fossils were unearthed, is a rich bed containing other prehistoric bones and artifacts. He says he plans to continue digging at the site to learn more about Tawa.

"We want to know how it grew, how the features changed as the animal got older," he said. "We also want to look at the anatomical details."

A description of the new dinosaur species is reported this week in the journal Science.

Gene action may lead to diabetes prevention, cure

2009-12-13T18:07:00.001-08:00

LOS ANGELES, Dec. 12 (Xinhua) -- A gene commonly studied by cancer researchers may provide answers to ways of fighting diabetes, a new study shows.

The gene, known in the science world as PFKFB3, is a regulator for metabolism, which plays a vital role in the development of diabetes, according to the study appearing in the Dec. Journal of Biological Chemistry.

The gene has been linked to the metabolic inflammation that leads to diabetes.

Understanding how the gene works means scientists may be closer to finding ways to prevent or cure diabetes, said the study conducted by researchers at Texas AgriLife Research.

"Because we understand the mechanism, or how the gene works, we believe a focus on nutrition will find the way to both prevent and reverse diabetes," said Dr. Chaodong Wu, AgriLife Research nutrition and food scientist who authored the paper with the University of Minnesota's Dr. Yuqing Hou.

Wu said the research team will collaborate with nutritionists to identify what changes or supplements in a diet will activate the gene to prevent or stop the progression of diabetes.

He believes nutritionists working with the biological chemists can help develop food consumption plans that either prevent people from developing metabolic inflammation or cause existing conditions to retreat.

"First we will need to identify what effective compounds will trigger the gene to regulate metabolism," Wu said. "Then we need to determine what combinations within foods are more effective."

Wu noted that while it is a major health concern in the U.S., obesity does not necessarily cause diabetes to develop; i.e., just because a person is overweight does not mean they have diabetes. Rather, "metabolic inflammation" causes or exacerbates the disease.

Metabolic inflammation is different from classic inflammation because there is no infection, virus or bacteria present, though the symptoms appear similar.

Gene Mutations Linked to Early-Onset Inflammatory Bowel Disease

2009-11-23T00:23:00.000-08:00

An international team has discovered that mutations in either of 2 related genes cause a severe and rare form of inflammatory bowel disease in young children. The discovery allowed the researchers to successfully treat one of the study patients with a bone marrow transplant.

Inflammatory bowel disease is a group of disorders that includes Crohn's disease and ulcerative colitis. The inflammation, or swelling, of the intestines can cause pain, damage the tissue and make the intestines empty frequently, resulting in diarrhea. Previous studies have identified dozens of genes and variants that affect the risk for adult-onset inflammatory bowel disease, but none that singly cause the disease.

An international research team set out to search for genetic risk factors for early-onset inflammatory bowel disease. They examined DNA from 2 unrelated families with children who were affected by the disease. The research team, which was supported by several sources, included scientists from NIH's National Center for Biotechnology Information (NCBI), University College London in the United Kingdom, Hannover Medical School in Germany and several other institutions.

The scientists found that mutations in either of 2 genes are sufficient to cause early-onset inflammatory bowel disease, as reported in the advance online edition of the New England Journal of Medicine on November 4, 2009. Screening 6 additional patients with early-onset colitis identified another mutation in one of the genes. The 2 genes code for the proteins IL10R1 and IL10R2. These proteins act together to receive signals from interleukin 10, a signaling molecule that plays a crucial role keeping the body's inflammatory responses in check. When either IL10R1 or IL10R2 is mutated, the signals from IL10 cannot be received, and the resulting inflammation causes tissue damage, especially in the gastrointestinal system.

One of the young patients who hadn't responded to other therapies was given a bone marrow transplant from a healthy sibling. Bone marrow transplants can cure genetic disorders when the affected gene is normally active in marrow-derived cells. However, because of the risks associated with the procedure, the transplants are used only in cases of severe disease. This patient showed dramatic improvement following the procedure and has remained in remission from inflammatory bowel disease for more than a year.

"This is an excellent example of how discovery of causative genes and mutations can enable clinicians to go from bench to bedside for an informed treatment of patients," says Dr. Christoph Klein of Hannover Medical School, who led the diagnosis and treatment effort.

"This discovery is a milestone in research on inflammatory bowel disease, and will enable us to gain further insights into the physiology and immunity of the intestine," says Dr. Erik Glocker of University College London.

DNA World

Chromosome In Situ Hybridization

DNA Nanoparticles Protocols

DNA and Evidence Collection Principles

Hop DNA Extraction Protocol

Transmission electron microscopy DNA sequencing

Yeast DNA and RNA Methods

Databases of Yeast Genetics

Two-Hybrid System

US Scientists Reverse Signs of Aging in Mice

Elderly mice restored to middle age

Gene therapy 'memory boost hope'

New Era for Human Genetics Begins

1000 Genomes Project focuses on genetic differences which could lead to greater understanding of disease, evolution

Getty Images/iStockphoto

Researchers May Some Day Treat Depression with Gene Therapy

Jessica Berman 21 October 2010

Scientists Discover Pain Genes

Jessica Berman | Washington 11 November 2010

Stem Cell Therapy Gaining Ground in Asia

Heda Bayron | Hong Kong 25 November 2010

Scientists say DNA provides 'historical archive'

Genes Predict Who Will Live to Age 100

Technique may also help predict disease

Photo: Photos.com

Gene Abnormality Found To Predict Childhood Leukemia Relapse

DNA&RNA Databases and Tools

Xinjiang discovery provides intriguing DNA link

Scientists hail 'revolutionary' kidney gene find

Autosomal dominant vs Autosomal recessive

Fossil Hunters and Their Amazing Achievements

What information about a genetic condition can statistics provide?

How are genetic conditions and genes named?

What are complex or multifactorial disorders?

Can changes in mitochondrial DNA affect health and development?

Can changes in the structure of chromosomes affect health and development?

Can changes in the number of chromosomes affect health and development?

Can a change in the number of genes affect health and development?

What kinds of gene mutations are possible?

Do all gene mutations affect health and development?

How can gene mutations affect health and development?

What is a gene mutation and how do mutations occur?

Top 50 Websites for Healthcare

Scientists describe 'secret of life' in 1953

Bioethics: Human-animal hybrid embryos

Human stem cells

Possible types of animal/human hybrid embryos

Proportions of human and animal DNA

Public opinion

The debate

Ethical issues

Arguments against creating human/animal embryos

Arguments in favour of creating human/animal embryos

Genes not to be patented: U.S. judge

Scientists make genetically-modified cow with high Omega-3 fatty acid level

DNA from Sebria may signal new species of human ancestor

US Scientists Unlock Clues to Mystery of Butterfly Migration

Photo: USFWS

Related Articles

Related Links

Earl Richardson

VOA - S. Schlender

Dr. Thomas Barnes/USFWS

Biomedical Videos

Free Biology Videos and Movies

Genetics and Birth Defects (Source:NIH)

Diseases and Genes

Scientists Crack Genetic Code of Two Common Cancers

Discovery could revolutionize cancer care, saving millions of lives

Scientists Discover New Species of Dinosaur

Paleontologists say the dinosaur they call Tawa, was about the size of a large dog, but with a longer tail.

Gene action may lead to diabetes prevention, cure

Gene Mutations Linked to Early-Onset Inflammatory Bowel Disease

An international team has discovered that mutations in either of 2 related genes cause a severe and rare form of inflammatory bowel disease in young children. The discovery allowed the researchers to successfully treat one of the study patients with a bone marrow transplant.