DISSERTATION RESEARCH: Identification and Characterization of Incompatibility Genes that Contribute to Postzygotic Reproductive Isolation Between Species of Mimulus

Duke University, Durham NC

Investigators

Abstract

Speciation occurs when a single species splits into two or more reproductively isolated populations. The evolution of reproductive isolating barriers among these descendent species is essential to prevent gene exchange and preserve species differences. Thus far, few studies have identified which genes cause reproductive isolation. This proposal focuses on one type of post-mating reproductive isolation, hybrid sterility, which is thought to evolve by an accumulation of genetic changes that are incompatible when they come together in species hybrids. The proposed research will investigate a simple genetic incompatibility that causes hybrid male sterility between two closely related species of monkeyflower, Mimulus guttatus and M. nasutus. The objectives of this project are to clone these hybrid sterility genes and to characterize their developmental and molecular functions. Establishing the molecular identities and functions of Mimulus "speciation genes" will be an important step towards understanding the evolutionary forces that shape species divergence. Furthermore, the proposed research will provide a detailed analysis of the coordination and timing of flower and pollen development in Mimulus, a model system for studies of floral adaptation and speciation. This project will also provide opportunities for high school and undergraduate students to conduct collaborative laboratory research.