Research Abstract |
Proper measures for sustainable use of aquatic bioresources are urgently needed. To take such measures to manage aquatic organisms is not an easy task, however, because it is usually difficult to understand their population structure and even to identify their eggs and larvae. Therefore, reliable DNA markers for population and species identification are needed to be much developed. This study focused on the mitochondrial DNA as a hopeful resource for such markers. In this study, we aimed to promote our analyses of complete mitochondrial genome of fishes and also to extend our target organisms to crustaceans and some other marine invertebrates in order to develop mitochondrial genomics of marine animals. We newly collected many specimens of fishes, crustaceans, and other marine invertebrates including those of rare but important species for comprehensive phylogenetic analyses. More than 200 species have been sequenced for their complete mitochondrial genomes, and much more number of species have been analyzed for their partial mitochondrial genomes. Those data were compared with the previous data from other species to examine their variability and characteristics. Based on those novel data from fishes, our fish mitochondrial genome databese, MitoFish, was updated. Using huge datasets of nucleotides obtained and powerful computing systems, we made extensive phylogenetic analyses, and proposed new phylogenetic hypotheses for various groups of fishes, crustaceans, and some other marine invertebrates with high reliability. On the basis of the phylogenetic trees newly obtained, we estimated divergence times of major lineages of teleostean fishes to reconstruct an evolutionary history of fishes.
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