UNDERSTANDING THE HOW AND WHY OF REPRODUCTION

As someone with roots in organismal biology, my curiosity has always come in two flavors: how and why. The how addresses proximal questions of genetic, cellular, and developmental mechanisms, and the why addresses larger evolutionary questions. The primary focus of my research is reproduction, which is of fundamental importance to human health and society, evolution, animal science, and conservation. Reproduction appeals to me as a system of inquiry because of its incredibly complex, multi-factorial nature, as well as overarching themes of conflict, cooperation, and coevolution between the sexes.

My system of choice is the Drosophila fruit fly. Not only is it one of the first genetic model organisms boasting a powerful arsenal of tools and resources, it exhibits remarkable phenotypic diversity across 2000+ species, and it claims the world’s longest known sperm in D. bifurca at 5.8 cm long. One major goal of my research program is to understand the functional significance of these giant sperm, how they interact with the female reproductive tract, how variation in sperm length is regulated, and how pleiotropy and modularity among sperm traits influences their evolutionary trajectory.

Complex interactions mediate the outcome of sperm competition, also known as paternity success. Sperm length interacts with sperm numbers as well as with length of the female’s coiled tubular sperm storage organ, the seminal receptacle (SR), in a way that is contingent on phenotypes of the first male, second male, and female. Sperm length and SR length are positively correlated across Drosophila species, a pattern that may be mediated by these functional sperm-SR interactions as well as by a genetic correlation between sperm and SR length.