Wolfner 97-23356 When animals mate, receipt of seminal fluid from the male often triggers changes in the female that influence fertility. This is particularly well-documented in insects. In D. melanogaster, post-mating changes in the female include the stimulation of egg-laying and sperm storage, a decrease in the female's lifespan, and a decrease in a female's receptivity to subsequent mating Most of these changes are caused by secreted products of the male's accessory gland. To how understand how accessory gland products (Acps) cause these changes in mated females, Dr. Wolfner will define the targets and modes of action of three Acps that she has shown to be important in postmating responses: 1. For Acp26Aa, a prohormone-like protein that stimulates egg-laying in mated female, she will use germline transformation rescue and ectopic expression assays to determine how proteolytic processing, and particular amino acid regions, mediate its activity. She will use biochemical and genetic approaches to determine whether Acp26Aa acts directly on reproductive tract targets or indirectly via neuroendocrine targets reached from the circulatory systems. 2. The glycoprotein Acp36DE is the first molecule having a genetically -proven and -manipulatable role in the widespread and important process of sperm storage. She will define functional domains of Acp36DE and determine whether Acp36DE's action depends on its demonstrated ability to simultaneously bind to sperm and to cells in the female genital tract. 3. She will use genetic and transgenic methods to determine the post-mating effects on lifespan and fertility of Acp62F, a new Acp with strong sequence similarity to a neurotoxin that affects sodium channels. She will also determine whether Acp62F affects sodium channels in neuromuscular preparations. In addition, she will continue to characterize nine other Acps in our collection to identify those with important functions, for future study. Understanding the triggers of post-m ating changes at the molecular level addresses important developmental questions about hormone action, reproductive physiology, behavior and fertility (including related evolutionary questions). In the long-term, it may provide information useful in designing biological pest controls.
