Date of Award

12-20-2020

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Biology

Advisor(s)

Dorus, Steve

Second Advisor

Pitnick, Scott

Keywords

Evolution, Reproduction, Sex, Sexual Selection

Subject Categories

Biology | Ecology and Evolutionary Biology | Evolution | Life Sciences

Abstract

Sexual reproduction involves complex coordination, and potentially competition, among the reproductive cells, fluids, and structures of all individuals involved. For internally fertilizing species, these interactions occur within the body of one sex, predominantly the female, or ovary-associated, reproductive tract. Thus, characterizing the dynamics of the female reproductive tract is critical to understanding the interactions that mediate reproductive success. Although there has been increasing movement toward revealing the active role of the female reproductive tract in shaping and influencing reproductive outcomes, our knowledge of this environment remains limited as a result of both historical biases and technical constraints. My dissertation advances our understanding of the function and evolution of the female reproductive tract through the detailed molecular characterization of Drosophila melanogaster female reproductive tissues and secretions. In my first chapter, I described the transcriptome of each of the constituent tissues of the Drosophila female reproductive tract. I identified rapidly evolving genes in each tissue that are putatively involved in female-ejaculate interactions. I also found that the female reproductive tissues had a coordinated response to mating suggesting the necessity of concordant changes to support post-mating functions. In my second chapter, I conducted a proteomics analysis of the female reproductive tract that demonstrates the unique composition and response to mating of the extracellular female reproductive tract fluid as compared to the intracellular tissue contents. The distinct characteristics of the female reproductive tract fluid emphasizes the necessity of investigating the extracellular female reproductive environment to establish the appropriate context for female-ejaculate interactions. In my third chapter I investigated the female reproductive tract glands and reported a novel function of their contribution to the composition and digestion of a mating plug formed by the ejaculate. The putative role of glandular secretions in the timing of sperm ejection represents a potential mechanism for post-copulatory sexual selection pressures exerted by the female reproductive tract. These interconnected studies create a framework for understanding the molecular identities and functions of the various aspects of the internal female reproductive environment. Together, the research presented here advances our understanding of the active role of the female in interactions that determine reproductive success and provides a foundation for future investigations into the evolution of the internal reproductive environment.

Access

Open Access

Available for download on Saturday, May 03, 2025

Share

COinS