Mating pheromones of Nematoda: olfactory signaling with physiological consequences

• Pheromones have now been chemically identified in many species.
• Ascarosides, a family of secondary metabolites, form an ancient family of pheromones.
• Species from multiple genera secrete ascarosides as mating pheromones.
• Male-derived pheromones trigger physiological changes in females and hermaphrodites.

Secreted pheromones have long been known to influence mating in the phylum Nematoda. The study of nematode sexual behavior has greatly benefited in the last decade from the genetic and neurobiological tools available for the model nematode Caenorhabditis elegans, as well as from the chemical identification of many pheromones secreted by this species. The discovery that nematodes can influence one another's physiological development and stress responsiveness through the sharing of pheromones, in addition to simply triggering sexual attraction, is particularly striking. Here we review recent research on nematode mating pheromones, which has been conducted predominantly on C. elegans, but there are beginning to be parallel studies in other species.