The relationship between sex and age in worms

A group of scientists studying sex pheromone in worms found that this pheromone simultaneously controls a stage in the worms' life cycle, the long-lived larval stage.

This finding, published in Nature June 23, shows for the first time that reproduction and life are related to each other by small molecules.

Scientists often focus on DNA and protein as the main biological factors of an organism, but they have realized that chemicals are smaller, but more structurally diverse - called 'small molecules' - are also an important part of a living organism. Frank Schroder, author of the article and researcher at Boyce Thompson Academy, said: 'They are of the same importance as genes'.

The researchers sought to identify pheromone sex hormones that attract C. elegans to hermaphrodites (this worm has no females). C. elegans, a tiny nematode, is a sample of organisms commonly used for reproductive and developmental research in worms.

C. elegans worm.(Photo: newsdesk.umd.edu)

To identify pheromone sex hormones, researchers examined chemical compounds produced by worms, gradually eliminating abilities until only certain substances remained. They found that a group of sugar-like chemicals called ascarosides work together to attract males.

Schroeder said: 'An interesting aspect is that in order to create this biological reaction, many compounds are required. A combination of chemicals does not have much effect, but two or three combinations provide a strong reaction. '

Surprisingly, this group of compounds also causes young worms to enter a long larval stage.

When food is scarce or the crowd is too crowded, young worms stop growing normally and enter the larval stage. In this form, they can survive without eating and reproducing for months - about 10 times the normal life of worms. When larvae find better grass, it will grow into adult worms and return to the normal aging process.

Schroeder: 'We often think that aging is a process of decline, but the evidence indicates that aging is also a stage of development . ' Researchers predict that pheromone hormones may also increase age in adult worms.

Schroder stressed: 'The next question is how do these compounds affect the mating behavior and coordination of development time at the molecular level. Does the same effect occur in other animals. We are looking for genetic pathways that can play a role in slowing the aging process. '

Why can the same chemical compound control both age and sex appeal? The way these chemicals work is not well understood, but scientists have long known that reproduction and age are related - if an organism can live longer, it often reproduce less. Schroeder concludes: 'The activity of these chemical compounds needs to be explored, but clearly they provide the first direct relationship between these two basic life functions'.