How drosophila detect volatile pheromones: Signaling, circuits, and behavior

Pheromones and the mechanisms to detect them have evolved to transmit biologically relevant information from one member of a species to another, often with miniscule amounts of chemical. In Drosophila, the fatty acid pheromone 11-cis-vaccenyl acetate (cVA) is a male-specific pheromone that functions as a courtship cue to ensure an appropriate partner is selected for mating. However, cVA also underlies other behaviors including aggression and aggregation. A specialized population of sensory neurons tuned solely to cVA mediates the detection of cVA pheromone. These neurons express a unique set of signal transduction machinery essential for detection of low levels of cVA in air. Stimulation of these neurons activates a labeled-line circuit to higher processing centers in the brain. These circuits trigger behavior outputs that are hardwired, but that can be modulated by learning. In this chapter we review the current state of our understanding of cVA pheromone biology in Drosophila, with emphasis on recent findings in pheromone detection mechanisms and the circuits underlying pheromone-induced behaviors.