Genes involved in sex pheromones discrimination and their context-dependent effect

Mate choice is based on the comparison of the sensory quality of potential mating partners and sex pheromones are important with regard to mate choice. In Drosophila melanogaster, male and female contact pheromones diverge both for their occurence and for their effects — respectively inhibitory and stimulatory — on male courtship. To investigate the genetic basis of sex pheromones discrimination in male flies, we experimentally selected, during 20 generations, lines in which males showed either the higher or the lower ability to discriminate sex pheromones. This experimental selection was carried out with wild-type and desat1 mutant genetic backgrounds in which parental males respectively showed high and low discrimination ability. Male perception of male and of female pheromones were separately affected during the process of selection. The comparison of transcriptomic activity between high and low discrimination lines revealed two genes which differently varied according to the genetic background. This suggests that male discrimination of sex pheromone depends on genes whose activity depends on the genetic context