Sequencing method yields fuller pictureJuly 18, 2007Sequence data for both chromosomes can be inferred under the right circumstances, USC biologists say. University of Southern California biologists have developed a method for sequencing both chromosomes of an organism. Their study appears in a recent issue of Genome Research. The statistical method is significant because when researchers announce they have sequenced an organism's genome, they really mean that they have created a mosaic of two chromosomes, said USC computational biologist Lei Li. "A mosaic means it's not real," Li said. Lead author and former graduate student Jong Hyun Kim, advised by Li and USC University Professor Michael Waterman, was able to infer a complete sequence of the chromosomes of Ciona intestinalis, a marine invertebrate, from existing sequencing data. Kim's method exploited the high rate of genetic mutations in the organism. Other organisms with high genetic variability, such as certain fish, also may be suitable. Because the human genome has a relatively low mutation rate, the method cannot be applied to people. However, Kim said, the method might be useful in sequencing parts of the human genome that display high variability. As a by-product of their analysis, the researchers added to growing evidence that so-called junk DNA may have a function after all. Recent studies have shown that junk DNA expresses proteins which may regulate gene function, and that sections of junk DNA have been highly conserved during evolution, suggesting that they play an important role. The Genome Research study confirms that many short sections of junk DNA are highly conserved, Li and Kim said. University of Southern California |
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| Related Chromosomes Current Events and Chromosomes News Articles Scientists at UA, collaborating institutions decode maize genome Scientists from the University of Arizona led by Arizona Genomics Institute director Rod A. Wing and from collaborating institutions have deciphered the complete genetic code of the maize plant for the first time. New map of variation in maize genetics holds promise for developing new varieties A new study of maize has identified thousands of diverse genes in genetically inaccessible portions of the genome. New techniques may allow breeders and researchers to use this genetic variation to identify desirable traits and create new varieties that were not easily possible before. New Maize Map to Aid Plant Breeding Efforts In a massive survey of genetic diversity in maize, also known as corn, researchers across the United States, have developed a gene map that should pave the way to significant improvements in a plant that is a major source of food, fuel, animal feed and fiber around the world. Chromosomes dance and pair up on the nuclear membrane Meiosis - the pairing and recombination of chromosomes, followed by segregation of half to each egg or sperm cell - is a major crossroads in all organisms reproducing sexually. Largest gene study of childhood IBD identifies 5 new genes In the largest, most comprehensive genetic analysis of childhood-onset inflammatory bowel disease (IBD), an international research team has identified five new gene regions, including one involved in a biological pathway that helps drive the painful inflammation of the digestive tract that characterizes the disease. NIH-funded researchers transform embryonic stem cells into human germ cells Researchers funded in part by the National Institutes of Health have discovered how to transform human embryonic stem cells into germ cells, the embryonic cells that ultimately give rise to sperm and eggs. A solution to Darwin's 'mystery of the mysteries' emerges from the dark matter of the genome Biological species are often defined on the basis of reproductive isolation. Ever since Darwin pointed out his difficulty in explaining why crosses between two species often yield sterile or inviable progeny (for instance, mules emerging from a cross between a horse and a donkey), biologists have struggled with this question. Common weed could provide clues on aging and cancer A common weed and human cancer cells could provide some very uncommon details about DNA structure and its relationship with telomeres and how they affect cellular aging and cancer, according to a team led by scientists from Texas A&M University and the University of Cincinnati (UC). CSHL-led team discovers rare mutation dramatically increasing schizophrenia risk An international team of researchers led by geneticist Jonathan Sebat, Ph.D., of Cold Spring Harbor Laboratory (CSHL), has identified a mutation on human chromosome 16 that substantially increases risk for schizophrenia. Standards for a new genomic era A team of geneticists at Los Alamos National Laboratory, together with a consortium of international researchers, has recently proposed a set of standards designed to elucidate the quality of publicly available genetic sequencing information. More Chromosomes Current Events and Chromosomes News Articles |
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