It’s almost Valentine’s Day, and love is in the air. Or in the waxy coating on your skin, if you are a vinegar fly. That’s where flies encounter pheromones that play an important role in regulating sexual attraction.
Flies use pheromones to ensure that they court and mate with members of the same species. As new fly species split off from a common ancestor, but continue to share the same environment, they need a way to rapidly diversify their pheromones to suppress inter-species mating. When members of two related species stop finding each other attractive, this helps prevent interbreeding.
But it’s more complicated than “she loves me, she loves me not.“
Because the perception and production of pheromones are mediated by different tissues and cellular pathways, evolving new mating pheromones requires a coordinated evolution of both the genes responsible for sensing the pheromones as well as the genes that produce them.
A new study in iScience led by Yehuda Ben-Shahar, PhD at Washington University in St. Louis identifies a link between the genetic instructions for the production and perception of sex pheromones. The research was conducted in collaboration with Jocelyn Millar from the University of California, Riverside.
Researchers reported that a single protein called Gr8a is expressed in different organs in male and female flies and appears to play an inhibitory role in mating decision-making. The findings point to one of the ways that flies could put up behavioral barriers to protect against mating with the wrong kind of partner.
“Mating pheromones often show rapid evolution,” said Ben-Shahar, a professor of biology in Arts & Sciences. “Because pheromonal communication requires a very robust and specific structural recognition of chemicals used as pheromones by the proteins that bind them in sensory neurons (chemoreceptors), it means that major molecular changes in either the receptor or the pheromone would reduce sexual attraction between males and females.”