Sex-Specific Fitness Consequences of the Female Immune Response to Insemination in Drosophila Melanogaster

The University Of Central Florida Board Of Trustees, Orlando FL

Investigators

Abstract

In many systems, females exhibit a strong, localized immune response to the male's ejaculate that has traditionally been viewed as a defense against sexually transmitted disease. However, the female response has been noted to kill sperm in some systems. In systems with intense sperm competition (i.e. systems where multiple ejaculates reside in the female's reproductive tract at any given time), males may interfere with the female's immune response in order to increase their sperm viability, thereby increasing their chance of fertilization success over rival males. To address this possibility, genes that code for female immune proteins and male ejaculate proteins will be manipulated in order to elucidate their potential effect on mating behavior, sperm viability and sperm competition. Specifically, three objectives will be addressed including (1) if the female immune response to insemination underlies the reduction in sperm viability commonly found among invertebrates, (2) if male fertilization success is constrained by the female immune response, and (3) the consequences of the male ejaculate on female immunity. The experimental design takes a comprehensive approach, examining numerous genes associated with a variety of physiological systems. Considering that reproduction and immunity are both highly conserved biological systems, there appears to be great potential for such an interaction to operate in a wide array of sexually reproducing systems. Thus, the immune system may play a key role in the evolution of mating systems and visa versa. The proposed research provides an ideal opportunity to promote scientific training and education. Specifically, the project provides independent research opportunities to undergraduate and graduate students interested in evolutionary biology, ecological immunity and learning molecular techniques.