Females of many species undergo dramatic behavioral and physiological changes following mating. In the vinegar fly Drosophila melanogaster, the model organism to be used in this study, mated females reject subsequent mating attempts, increase rates of ovulation and egg-laying, store sperm for several weeks, and show a change in lifespan. Proteins transferred to females by males during mating, as well as proteins produced by females, are partially responsible for such changes. This study will focus on a particular class of proteins potentially involved in reproduction, consisting of proteases and protease inhibitors, whose biochemical role is to regulate the cleavage of other proteins. Genes encoding these reproductive proteases and protease inhibitors will be characterized from evolutionary and functional standpoints.
This work will shed light on the roles of reproductive proteases and protease inhibitors in other species, with potential practical extensions to pest control and human disease. For example, there is potential to manipulate the reproductive processes of pest species (i.e. prevent reproduction) through proteins similar to those under investigation in this study. Furthermore, at least one human disease, prostate cancer, is associated with a mutation in a reproductive protease inhibitor. Since the vinegar fly is more experimentally tractable than most other organisms, it represents a good system in which to learn about the functions and evolution of reproductive proteases and protease inhibitors. The lessons learned from these experiments should find applicability in organisms of economic concern, and in humans.
