Drosophila Chemoreceptors: A Molecular Interface Between the Chemical World and the Brain

Chemoreception is essential for survival. Feeding, mating, and avoidance of predators depend on detection of sensory cues. Drosophila contains diverse families of chemoreceptors that detect odors, tastants, pheromones, and noxious stimuli, including receptors of the odor receptor (Or), gustatory receptor (Gr), ionotropic receptor (IR), Pickpocket (Ppk), and Trp families. We consider recent progress in understanding chemoreception in the fly, including the identification of new receptors, the discovery of novel biological functions for receptors, and the localization of receptors in unexpected places. We discuss major unsolved problems and suggest areas that may be particularly ripe for future discoveries, including the roles of these receptors in driving the circuits and behaviors that are essential to the survival and reproduction of the animal.

TrendsOdorant receptors (Ors) have been found to activate an increasing number of behavioral circuits.Gustatory receptors (Grs) are expressed in a wide diversity of organs. Emerging results reveal roles in an expanding repertoire of functions, extending beyond chemoreception.Ionotropic receptors (IRs) are expressed not only in olfactory organs but also in taste organs. A large clade has recently been found to be expressed in all taste organs of the fly.Ors, Grs, and IRs all have roles in the sexual behavior of the fly.