The nature and nurture of female receptivity: A study in Drosophila melanogaster

Reproduction is a cooperation between a male and a female to produce offspring. Males initiates reproduction and seduce the female. Females decide whether they accept the advances of the male. Female receptivity, the likelihood to accept mating, is therefore very influential on whether a mating is taking place. In this thesis, I investigated what internal and external factors influence female receptivity. What factors can persuade a female to accept the male’s advances and which genes of the female are important to determine receptivity? In this thesis, I describe the influence of food availability and social context on female receptivity and how this detected. In environments with high food availability or high social density, females increase receptivity after mating but not as virgin. Of the genes determining female receptivity, two related odorant receptor genes are necessary: one is necessary only for female receptivity after mating, whereas the other might be involved both before and after mating. Additionally, variation in receptivity and the underlying genes show that the genetic architecture of receptivity before and after mating are uncorrelated. Genes underlying variation in receptivity after mating seem more often associated to learning and memory processes, whereas genes for virgin receptivity are related to olfaction. Together these data suggest that receptivity before and after mating have different mechanisms and that receptivity after mating is a more complex behaviour involving learning and memory processes and influenced by environmental factors possibly to match the investment in reproduction to environmental resources.