Washington, Nov 25 : Female flies have a unique ability to turn back the biological clock and extend lifespan at the same time, according to a new study.
It has long been known that "the more you reproduce, the shorter you're going to live," said senior author John Tower, associate professor of biological sciences at USC College.
However, female flies turned out to be an exception
Tower and graduate student Yishi Li screened 8,000 genes in search of ones that could make older flies lay more eggs and found two such proteins.
When older female flies were altered to over-express either of these two genes, their lifespan increased by 5 to 30 percent and produced more offspring.
Tower believes that the genes are boosting activity of stem cells in the flies' reproductive system.
Stem cell activity declines with age, and reproduction in older flies could not happen without a return of stem cells to peak form.
"This would appear to be stimulating the stem cells to divide more in the old fly and therefore produce more offspring," Tower said.
If they did, over-expression of the two genes would seem to act as a fountain of youth for the entire organism.
"It both makes females lay more eggs and live longer, so it really argues against any kind of obligatory tradeoff between reproduction and lifespan," Tower said.