Dissertation Research: The Evolution of Hybrid Incompatibility in the Beetle, Tribolium castaneum

Indiana University, Bloomington IN

Investigators

Abstract

The goal of this project is to understand the evolution of complex genetic architectures and the role they play in the early stages of speciation. The study involves three phases: (1) Line crosses between flour beetles (Tribolium castaneum) collected from populations around the world to produce all 1st and 2nd generation hybrids. These crosses are then analyzed statistically to quantify the contribution of genetic interactions; (2) Population structure - for the line-cross populations, we will assay mtDNA sequence and microsatellite marker variation to quantify the genetic divergence among them; and, (3) Mapping - A microsatellite linkage map will be assembled to find regions of the genome responsible for hybrid incompatibility. Gene interactions are important to speciation because negative genetic interactions are necessary to lower hybrid fitness. On the other hand, a major reason for the success of commercial agriculture is increased hybrid productivity. This study will contribute to the understanding of gene interactions and the understanding of how geographic and genetic divergence among related populations leads to decreased fitness in some cases but increased fitness in others.