Molecular evolution and ecological adaptation of gender-associated mitochondrial genomes in bivalves

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I study an unusual system of mitochondrial DNA inheritance present in bivalve mollusks. Unlike otheranimals, 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 thathave been proposed to explain the origin and maintenance of this unusual system of mitochondrial DNAinheritance including whether it allows for natural selection to improve sperm performance in these mussels orwhether 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 will also apply to other animal groups. This knowledge would be of general interest and value to geneticists, invertebrate biologists and zoologists. The advancement of pure knowledge in the area of sex determination in bivalves may have applications in the field of aquaculture and 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 evolution of mitochondrial DNA. For example, my research program will provide essential data for interpreting DNA sequences for a particular gene known as Cox1, which is used as the basis of the "Consortium for the Barcode of Life" initiative. This is an attempt to use DNA sequence data to identify all species of animals in the world using a simple, inexpensive test. The 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.