DISSERTATION RESEARCH: Biochemistry and Molecular Evolution of Female Reproductive Tract Proteins in Drosophila

University Of Arizona, Tucson AZ

Investigators

Abstract

Extensive research across a broad range of taxa has revealed that proteins involved in sexual reproduction are often subject to adaptive evolution. The evolutionary forces which underlie this pattern remain unclear. Although several theories postulate a role for coevolution between males and females, this has never been demonstrated in an internally fertilizing organism. The proposed research explores the hypothesis that intersexual coevolution has played a role in the diversification of three families of digestive proteases in Drosophila arizonae female reproductive tracts. Specifically, the research will explore the unique evolutionary history of these gene families, identify functional differences between paralogs in a single gene family, and determine how these functional differences relate to interaction with specific seminal proteins. The proposed research will make two major contributions to the study of reproduction. First, it will represent the first identification of biochemical interactions between specific seminal proteins and female reproductive tract proteins, which is critical elucidating the molecular basis of intersexual dynamics in internal fertilizers. Second, it will significantly increase our currently sparse knowledge of biochemical function and molecular evolution of female reproductive tract proteins. This knowledge is of broad significance, as reproductive proteins often exhibit similar functions across large evolutionary distances. The proposed research will additionally represent a rare case in which detailed studies of molecular evolution are combined with functional assays of the proteins involved. The results therefore have important implications for understanding the connection between sequence evolution and biochemical evolution.