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. Hereditary information flows from parents to offspring not just through DNA but also through the millions of proteins and other molecules that cling to it. These modifications of DNA, known as "epigenetic marks," act both as a switch and a dial - they can determine which genes should be turned on or off, and how much message an "on" gene should produce. http://www.physorg.com/news147015705.html Biology Thu, 27 Nov 2008 13:41:45 EST news147015705