Study Unveils the Link Between Sex Compounds and Lifespan

by VR Sreeraman on Jul 24 2008 7:14 PM

In a study on sex pheromones in a tiny worm, scientists have discovered a link between reproduction and lifespan through so-called small molecules.

After realising the importance of these "small molecules," the researchers have found that the same family of pheromones also controls a stage in the worms' life cycle, called the long-lived dauer larva.

In this study, researchers wanted to identify the sex pheromone that attracts male C. elegans worms to the more common hermaphrodites (this worm species has no females).

For spotting the sex pheromone, scientists tested mixtures of chemicals produced by the worms, till the time only a few remained. It was found that it was the work of a handful of sugar-like chemicals called ascarosides, which attracted the males.

"One interesting aspect is that a whole family of compounds is necessary to elicit a biological response. One by itself doesn't do much, but two or three together give a strong response," Nature quoted Frank Schroeder, last author of the paper and a scientist at the Boyce Thompson Institute, as saying.

In fact, the same group of compounds was also found to trigger young worms to enter the long-lived dauer stage.

Young worms enter the dauer stage when they stop developing normally in the scarcity of food or in case the colonies become crowded. In dauer stage, the worms can live without eating or reproducing, for months - about ten times longer than the worm's normal lifespan. At a time when the dauer finds greener pastures, it finally develops into an adult and resumes its normal aging process.

"We usually think of aging as a process of decay, but evidence is accumulating that aging is a stage of development like anything else," said Schroeder.

According to speculations, the dauer pheromone may also increase the lifespan of adult worms.

"The next question is how these compounds influence mating behavior and developmental timing on the molecular level and whether a similar effect is possible in other animals. We're looking at genetic pathways that could potentially play a role in delayed aging," said Schroeder.

The study is published in the recent issue of Nature online.