Optimal reproduction requires successful interaction between females and males -- including at the physiological and molecular levels. Along with sperm, insect males provide their mates with seminal proteins whose effects on females can improve reproductive success. In Drosophila melanogaster, these seminal proteins (accessory gland proteins; Acps) increase egg production and laying by the female, facilitate her ability to store sperm, and modify her receptivity to re-mating, although they also decrease her longevity.

Acps provide a tool for gaining insight into how the physiology of the female is modified by mating, and for the underlying molecular interactions. After reviewing the suite of Drosophila Acps in terms of their molecular nature, reproductive function and evolutionary dynamics, I will present examples of Acp influences on female physiology or its regulators. I will discuss biochemical, genetic and transgenesis experiments on ovulin, an Acp that regulates ovulation. These results have defined domains important for ovulin's structure and function, and have begun to define the molecular players that mediate ovulin's processing -- which requires cooperation between male and female. I will also present results that show that Acps promote muscle contractions in the reproductive tract that can facilitate sperm storage by the female. I will summarize how the above studies and others provide mechanistic as well as evolutionary perspectives on cooperation and/or conflict between the sexes in insect reproduction.