UC San Diego

Polyandry, where females mate with multiple males during their lifetime, enhances female reproductive fitness in many animal species. In the polyandrous insect species Drosophila melanogaster, females exhibit a rapid decline in receptivity after mating through well-characterized neuromodulatory mechanisms. However, the process by which mated females regain receptivity remains underexplored. My thesis project aims to investigate how pheromone cues and post-mating diet regulate female receptivity recovery. Or67d olfactory receptor neurons (ORNs) are activated by a male-specific pheromone, 11-cis-vaccenyl acetate (cVA), and promote mating in virgin females. This makes Or67d ORNs strong candidates for regulating mated female receptivity. Using a remating competition assay, I found that Or67d ORNs indeed promote remating in female Drosophila. Moreover, mated female Drosophila show a strong preference for dietary protein, leading me to explore whether a high-yeast diet facilitates remating. I found that a high-yeast diet enhances remating in both wildtype and Or67d mutant flies, with a more pronounced effect observed in wildtype flies. Additionally, remating further increased egg-laying in females fed a high-yeast diet, suggesting a synergistic interaction between polyandry and a protein-rich diet. Together, the project revealed the roles of olfactory input and dietary protein in regulating the receptivity of mated female Drosophila.