Biomarkers and Programmed Aging
Via EurekAlert!, recent research in which biomarkers of cellular aging - genetic activity in this case - and programmed aging are discussed in the same breath. In fact these are quite separate topics; programmed aging is not necessary to explain common forms of change in gene expression with tissue age, nor longevity differences between species. "Why animals and even people age at different rates prompted Kim to look deeper into the processes that control aging. His new study suggests that the cell has a molecular homeowner that keeps up repairs until a predetermined time, when the owner picks up the welcome mat and moves out. Once that process kicks off, the decay happens as a matter of course. The homeowners in tortoise cells stick around for hundreds of years delaying the decay, while those in fly cells move out within weeks ... [the] work doesn't identify what triggers that process, it does provide a way of detecting the point a cell has reached in its life span." Remember that cellular longevity doesn't necessarily have to have anything to do with your longevity.
Link: http://www.eurekalert.org/pub_releases/2006-07/sumc-wim071906.php