According to a press release (18 January 2002), researchers at the University of California at San Francisco have found that stem cells for eggs and sperm also control aging in the roundworm C. elegans. The unsuspected role may find parallels in other organisms including humans, they suggest.
The finding shows for the first time that genes act in the adult animal to control its rate of aging. The stem cells, it seems, can modify lifespan even as aging is proceeding. The key stem cells, the scientists found, are not those that actually become egg or sperm, but their sister cells from the same stem cell pool, known as "proliferating germline stem cells," that divide continuously in the animalís reproductive tissues. Their study is reported in the 18 January 2002 issue of Science.