http://www.physorg.com/ en-us Physorg.com internet news portal provides the latest news on science including: Physics, Nanotechnology, Life Sciences, Space Science, Earth Science, Environment, Health and Medicine. Keeping the genome stable is a "sister act" of matched chromatids - the pairs of the double helix DNA molecule that exist during the chromosome duplication in the S phase of the cell cycle. http://www.physorg.com/news134915706.html Medicine & Health Thu, 10 Jul 2008 13:35:06 EST news134915706