Grant: Discovery Grants Program - Individual

I study an unusual system of mitochondrial DNA inheritance present in bivalve mollusks. Unlike other animals, some bivalves possess two distinct gender-associated mtDNA lineages rather than just a single, female transmitted mtDNA lineage found in most animals. I am interested in testing various hypotheses that have been proposed to explain the origin and maintenance of this unusual system of mitochondrial DNA inheritance including whether it allows for natural selection to improve sperm performance in these mussels or whether these gender-associated genomes might play a role in sex determination. The distinct male and female transmitted mtDNA genomes found in marine mussels also undergo recombination, a phenomenon that was, until recently, not thought to occur in animal mtDNA genomes. My approach to studying this unusual system of mitochondrial DNA inheritance includes a combination of sperm motility analyses, sperm metabolic activity assays, and whole mitochondrial genome sequencing assays. The anticipated outcome of my research is to advance our understanding of basic biological processes primarily in bivalves but this knowledge might also apply to other animal groups. This knowledge would be of general interest and value to geneticists, invertebrate biologists and zoologists generally. The advancement of pure knowledge in the area of sex determination in bivalves may have applications in the field of aquaculture or in the development of biological controls for invasive freshwater mussel species through artificial control of sex ratios. My research has broad implications for interpreting the molecular evolution of mitochondrial genomes. For example, my research program will provide essential data for interpreting bivalve CoxI sequences, which are the basis of the ""Barcode of Life"" initiative. Correct interpretation of DNA barcodes of native marine and freshwater mussels will be increasingly important as these species face threats from global climate change and global transport of invasive bivalve species.