Mitochondrial genome map of Asian Crassostrea oysters. All 39 genes are coded on the same DNA strand. Genes for proteins and rRNAs are shown with standard abbreviations. Genes for tRNAs are designated by a single letter for the corresponding amino acid with two leucine tRNAs and two serine tRNAs differentiated by numeral. The two tRNA duplications of methionine, lysine and glutamine are named trnM1, trnM2, trnK1, trnK2, trnQ1 and trnQ2, respectively. The length of five mt genomes is indicated at the lower right-hand corner.