An international team that includes researchers from the National Human Genome Research Institute (NHGRI), part of the National Institutes of Health (NIH), has discovered that mammalian chromosomes have evolved by breaking at specific sites rather than randomly as long thought - and that many of the breakage hotspots are also involved in human cancer.
In a study published in the July 22 issue of the journal Science, a team of 25 scientists from the United States, France and Singapore compared the organization of the chromosomes of eight mammalian species: human, mouse, rat, cow, pig, dog, cat and horse. Using sophisticated computer software to align and compare the mammals genetic material, or genomes, the team determined that chromosomes tend to break in the same places as species evolve, resulting in rearrangements of their DNA. Prior to the discovery of these breakage hotspots, the prevailing view among scientists was that such rearrangements occurred at random locations.
To learn more about the rapidly growing field of comparative genomics, go to www.genome.gov/11509542. The genomes of a number of organisms have been or are being sequenced by the large-scale sequencing capacity developed by the Human Genome Project, which was led in the U.S. by NHGRI and the Department of Energy. A complete list of organisms and their sequencing status can be viewed at www.genome.gov/10002154.
High-resolution photos of dog, cat, cow, rat and other organisms under study by NHGRIs Large-Scale Sequencing Program are available at www.genome.gov/10005141.
Message posted by: Rashmi Nemade