DISSERTATION RESEARCH: Within species reproductive isolation: does chloroplast inheritance mediate cytonuclear incompatibility?

University Of Virginia Main Campus, Charlottesville VA

Investigators

Abstract

New species arise as populations within a species become differentiated and are no longer able to produce viable hybrid offspring. Even though such divergence occurs in many species, however, most do not undergo speciation. What prevents this speciation process from occurring? In the plant species Campanulastrum americanum reduced viability of between-populations hybrids is correlated with divergence in the chloroplast genome. Offspring of these low performing hybrids, though, often show complete recovery. Chloroplast and mitochondria genomes are typically inherited only from the mother. However, hybridization between divergent populations may lead to their inheritance from both the mother and father. This project will test whether inheritance patterns of the chloroplast are affected by hybridization, and if inheriting the chloroplast from both parents allows this species to overcome reduced offspring viability due to chloroplast divergence. The proposed work will enhance graduate training by supporting a new collaboration for the purpose of learning a technique for quantifying chloroplast inheritance patterns. In addition, this work will allow for the continued training of undergraduate students from diverse backgrounds through independent research projects. Finally, the proposed research will advance our understanding of how new species form, and whether altered inheritance patterns of the organelle genomes, such as the chloroplast, may result in slowing the speciation process.