DISSERTATION RESEARCH: Impacts of metabolic differences on cytonuclear coevolution

Colorado State University, Fort Collins CO

Investigators

Abstract

Organisms harvest organic fuel to produce cellular energy through the metabolic pathway known as oxidative phosphorylation. This critical process is carried out along a chain of interacting proteins that are encoded by two separate genomes, mitochondrial and nuclear, that must cooperate to maintain functional integrity. Levels of energy demand directly impact the molecular evolution of these metabolic genes. In birds, the high energy demand associated with flight has been correlated with molecular patterns that reflect conserved protein function. There exists a wide range of metabolic demands across animals, but the impact of such differences on protein evolution remains largely unexplored. Salamanders provide a unique opportunity to examine the impacts of metabolic demand on molecular evolution due to their extremely low metabolic requirements, which allow them to tolerate higher levels of protein variation than most other vertebrates. This study will analyze patterns of molecular evolution to determine what aspects of protein structure must be maintained to retain functional integrity of metabolic genes. This goal will be met by sequencing large portions of the highly variable mitochondrial and nuclear genomes of several salamander species. This study will yield a comprehensive analysis of the forces shaping the molecular evolution of the core proteins underlying aerobic metabolism. These results will provide an understanding of the molecular underpinnings of energy demand, which may aid in understanding the origin of genetic diseases associated with mitochondrial mutations. Two undergraduates and one graduate student will be trained in genomics and bioinformatics through this research.