Genomic Coadaptation, Extrinsic Interactions, and Reproductive Isolation in Tigriopus Californicus

University Of North Carolina At Chapel Hill, Chapel Hill NC

Investigators

Abstract

A more complete understanding of biological diversity and its generation requires a thorough investigation of the mechanisms that underlie divergence into distinct lineages (speciation). This proposal seeks to use a model system (the intertidal copepod Tigriopus californicus) to untangle the initial phases of diversification. Genetically differentiated populations of this copepod species can be crossed and studied in the laboratory to gain insights into the genetic factors that cause reproductive isolation between them. In this system reproductive isolation is only partial between populations (i.e. speciation is not yet complete). These copepods therefore allow investigation of the earliest stages of speciation, providing a useful contrast to studies in other systems in which there is complete reproductive isolation. One specific genetic system that will be examined is the mitochondrial electron transport system, which is responsible for energy generation in eukaryotes. Interactions between genes in this system appear to result in low hybrid fitness, forming part of the basis for reproductive isolation in these copepods. The significance of the proposed work is two-fold. First, an understanding of the genetic basis of reproductive isolation in this system will help to illuminate the process of speciation in animal taxa. Second, a specific focus on the interacting genes in the electron transport system could yield insights into adaptive changes involving mitochondrial energetics. The proposed research will include both graduate and undergraduate training and will involve both underrepresented minorities and women in the research process.