Washington, Oct. 24 (Reuters): Want to live to be 500'
You don’t even have to get decrepit — but you do have to tolerate a little genetic tinkering and, oh yes, the removal of your reproductive organs.
Scientists at the University of California San Francisco said they had created worms that lived six times longer than normal. The researchers, who have been working for several years to make long-lived worms, said their tiny roundworms lived for three months or longer, as compared to 18 or 20 days for a normal worm.
“In human terms, these animals would correspond to healthy, active 500-year-olds,” they wrote.
Writing in the journal Science, they said their findings could have implications far beyond worms, as the gene they tinkered with also affects lifespans in higher animals such as mammals.
Cynthia Kenyon and colleagues have been working with roundworms called Caenorhabditis elegans. The soil-dwelling roundworms are favoured by genetic researchers because while they have relatively simple genomes, they share much in common with other animals, including humans.
The researchers had already found several ways to make the worms live longer by changing a variety of genes and environmental factors.
One gene that interested them is IGF-1 or insulin growth factor — a gene that helps regulate how the body uses insulin, itself a regulator of metabolism.
Certain mutations of the gene double a worm’s lifespan by weakening the effects of IGF-1, and removing their reproductive systems doubles it again.
Kenyon’s team added another layer of tinkering, breeding worms with the mutation to IGF-1 and then using a genetic technique called RNA interference to further weaken the gene’s function. These worms lived even longer.
“Moreover, when we removed the reproductive systems of these ... animals, they lived six times as long as normal,” they wrote. “Whereas the mean lifespan of wild type (unaltered worms) was 20 days, these animals had mean lifespans of 124 days.”