The microscopic roundworm is at it again, offering dramatic insights into the factors that regulate aging, at least in C. elegans. This time, UCSF researchers report that lessening the nematode's ability to perceive its environment - presumably through smell or taste -- increases its lifespan by more than a third.

Instead of living for two-plus weeks, the animals live three or four weeks -- the equivalent of a jump of from, say, 90 to 130 years in humans -- and remain youthful during this time.

The finding, reported in the December 16 issue of Nature, does not mean that people should start pinching their noses. What it does suggest, the researchers say, is that chemical signals from the environment, perhaps pheromones or the smell or taste of something in their food, influence the nematode's rate of aging, probably by acting on a hormone signaling system.

As many fundamental biological processes have been conserved between the worm and higher species, it is possible, the researchers say, that environmental signals also influence the lifespan of mammals, including humans.

While the chemical signals affecting the roundworm's lifespan have not been identified, the researchers say they most likely provide information that's crucial to the survival of the organism. They could, for instance, be pheromones that reflect population density, or compounds that originate from organic material, reflecting food availability.

"A lot of people think lifespan is something that's fixed within the individual organism, but this study suggests that the rate of the aging process is something that can be influenced by external factors, and that something as simple as signals in the environment can have a big effect on it," says Cynthia Kenyon, PhD, the Herbert Boyer Professor of Biochemistry and Biophysics at UC San Francisco and the senior author of the study. "It might be advantageous for worms to have different lifespans under different conditions, such
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Contact: Jennifer O'Brien
jobrien@pubaff.ucsf.edu
415-476-2557
University of California - San Francisco
15-Dec-1999