One of the most fundamental processes in biology is the establishment of the male and female gender. Gender choice is generally determined by regulatory genes controlling sexual differentiation, physiology and behavior. Sexual behaviors are of particular interest: first, they can vary widely between the two sexes within a species or/and between same-sex individuals from closely related species. Consequently, these behaviors play a central role in the fitness and evolutionary success of a species. Second, sexual behaviors are robust, innate and in general complex, involving many sensory modalities. Therefore, they can serve as model behaviors for investigations into complex neural circuits. Drosophila represents one of the best-characterized higher animals at the genetic and behavioral level. Moreover, the involvement of vision, chemoreception and audition offers ample opportunity to study this behavior from a variety of different angles. Recently, direct evidence for a pheromone receptor in male courtship was provided through the identification of a male-specific gustatory receptor gene, Gr68a. This gene is essential for the identification of a female partner during the male mating ritual. The goal of the presented study is to identify and characterize other pheromone receptors involved in male courtship; these receptors are likely to be found among the seven additional Gr genes closely related to GR68a and are proposed to control other aspects of male courtship. The proposed research will establish a framework of structural and molecular components that mediate an essential behavior common to most animals. Moreover, it will provide novel insights into how chemosensory inputs are transduced to the brain and integrated with other sensory inputs to generate a complex neuronal circuit. Efforts to recruit graduate and undergraduate are very successful (two undergrads, Meister and McNealy, co-authored a paper in 2001). Currently, a postdoc, three graduate and five undergraduate students are working in the PI's lab. Findings are disseminated through publications in international journals and scientific conferences. Moreover, they have also been reported in mainstream media, including BBC (Leading Edge, radio science news program).
