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Why does a snake have 25 or more rows of ribs, whereas a mouse has only 13? The answer, according to a new study, may lie in "junk DNA," large chunks of an animal's genome that were once thought to be useless. The findings could help explain how dramatic changes in body shape have occurred over evolutionary history. Scientists began discovering junk DNA sequences in the 1960s. These stretches of the genome-also known as noncoding DNA-contain the same genetic alphabet found in genes, but they don't code for the proteins that make us who we are. As a result, many researchers long believed this mysterious genetic material was simply DNA debris accumulated over the course of evolution. But over the past couple decades, geneticists have discovered that this so-called junk is anything but. It has important functions, such as switching genes on and off and setting the timing for changes in gene activity. 

Researchers analysed the genomes of 51 individuals who lived between 45,000 years ago and 7,000 years ago. The results reveal details about the biology of these early inhabitants, such as skin and eye colour, and how different populations were related. It also shows that Neanderthal ancestry in Europeans has been shrinking over time, perhaps due to natural selection. The study in Nature journal shines a torchlight over some 40,000 years of prehistory, showing that ancient patterns of migration were just as complex as those in more recent times.

A cornerstone of modern biomedical research is the use of mouse models to explore basic pathophysiological mechanisms, evaluate new therapeutic approaches, and make go or no-go decisions to carry new drug candidates forward into clinical trials. Systematic studies evaluating how well murine models mimic human inflammatory diseases are nonexistent. Here, we show that, although acute inflammatory stresses from different etiologies result in highly similar genomic responses in humans, the responses in corresponding mouse models correlate poorly with the human conditions and also, one another.

Redwood trees, those ancient living monuments to California's past, are as mysterious to science as they are magnificent, so a team of researchers led by a San Francisco conservation group is attempting to unlock the genetic secrets of the towering conifers. Scientists affiliated with the nonprofit Save the Redwoods League are attempting for the first time to sequence the genomes of coast redwood trees and their higher-elevation cousins, the giant sequoias, a complex and expensive undertaking that experts hope will help preserve the trees' ancient groves as the climate changes over the next century.

A British researcher has received permission to use a powerful new genome editing technique on human embryos, even though researchers throughout the world are observing a voluntary moratorium on making changes to DNA that could be passed down to subsequent generations.

In a unique twist on human genomics studies that seek to identify genetic variants linked to human disease, researchers have combined whole-exome sequencing of 50,726 adults with the individuals' long-term electronic health record (EHR) data. The effort, by researchers at the Geisinger Health System in Pennsylvania and Regeneron Genetics Center, a subsidiary of New York-based Regeneron Pharmaceuticals, has yielded novel disease-linked variants, including loss-of-function alleles. The team behind the project, called DiscovEHR, has also found that about one in 30 of the individuals harbors a deleterious genetic variant for which a screen or treatment already exists. The group's analysis is described in two papers published today (December 22) in Science.

Researchers have made dramatic inroads into the study of polygenic and other complex human diseases, due in large part to knowledge of the human genome sequence, the generation of widespread markers of genetic variation, and the development of new technologies that allow investigators to associate disease phenotypes with genetic loci. Although polygenic diseases are more common than single-gene disorders, studies of monogenic diseases provide an invaluable opportunity to learn about underlying molecular mechanisms, thereby contributing a great deal to our understanding of all forms of genetic disease.

The mouse is the leading organism for disease research. A rich resource of genetic variation occurs naturally in inbred and special strains owing to spontaneous mutations. However, one can also obtain desired gene mutations by using the following processes: targeted mutations that eliminate function in the whole organism or in a specific tissue; forward genetic screens using chemicals or transposons; or the introduction of exogenous transgenes as DNAs, bacterial artificial chromosomes (BACs) or reporter constructs. The mouse is the only mammal that provides such a rich resource of genetic diversity coupled with the potential for extensive genome manipulation, and is therefore a powerful application for modeling human disease.

video clips of diverse women scientists and STEM role models  3700 video clips from 160 inspiring women - biochemists, biomedical researchers, chemists, forensic scientists, geneticists, genomic sciences, geologists, icthylogists, meterologists, oceanographers

The advent of increasingly powerful and inexpensive DNA sequencing methods is changing many aspects of genetics research. In particular, human genome sequencing is transforming our understanding of many aspects of human biology and medicine. However, we must be careful to remember that genes alone do not determine our futures-environmental factors and chance also play important roles.

A stride to understand the cancer and move towards its prevention, this time experts from around the world involved in searching the genome of cancer have analyzed the mutational signatures, the processes of mutation in the DNA of cells (which are always in the origin of cancer) and they follow a fixed pattern.

The early stages of embryonic development shape our cells and tissues for life. It is during this time that our newly formed cells are transformed into heart, skin, nerve or other cell types. Scientists are finding that this process is largely controlled not by the genome, but by the epigenome, chemical markers on DNA that tell cells when to turn genes on and off. Now, studying zebrafish embryos, researchers at Washington University School of Medicine in St. Louis have shown that the epigenome plays a significant part in guiding development in the first 24 hours after fertilization.

Nature: research findings by chromosome number

Genetic research is leading to the development of more genetic tests that can be used for the diagnosis of genetic conditions. Genetic testing is available for infants, children, and adults. Genetic tests can be used to diagnose a disease in an individual with symptoms and to help measure risk of developing a disease. Adults can undergo preconception testing before deciding to become pregnant, and prenatal testing can be performed during a pregnancy. Results of genetic tests can help physicians select appropriate treatments for their patients.

Tweaking the human genome with current and future gene-editing tools could lead to sophisticated treatments and prevention strategies for disease. The promise of those applications is reason enough to move forward with such work in the lab and clinic, albeit cautiously, the dozen scientists and bioethicists who organized the International Summit on Human Gene Editing said today after three days of deliberation and presentations in Washington, D.C.

The agricultural revolution was one of the most profound events in human history, leading to the rise of modern civilization. Now, in the first study of its kind, an international team of scientists has found that after agriculture arrived in Europe 8,500 years ago, people's DNA underwent widespread changes, altering their height, digestion, immune system and skin color. Researchers had found indirect clues of some of these alterations by studying the genomes of living Europeans. But the new study, they said, makes it possible to see the changes as they occurred over thousands of years.

Over recent decades, scientists have made various discoveries about DNA methylation and how vital it is to a number of cellular processes such as embryonic development, X-chromosome inactivation, genomic imprinting, gene suppression, carcinogenesis and chromosome stability. Researchers have linked abnormal DNA methylation to several adverse outcomes, including human diseases.

We've harnessed electricity, sequenced the human genome, and eradicated smallpox. But after billions of dollars in research, we haven't found a solution for a disease that affects more than 14 million people and their families at any given time. Why is it so difficult to cure cancer? Kyuson Yun explains the challenges.

Following on the achievements of Chinese researchers, scientists in the United States have used CRISPR to manipulate the genomes of viable human embryos, MIT Technology Review reported yesterday (July 26). The work, not yet published, reportedly corrected defective genes from sperm donors in dozens of embryos, which were allowed to grow for several days.