title: The complete mitochondrial genome of the hard clam Meretrix meretrix.
abstract: Veneridae is a diverse, commercially important, and cosmopolitan family. Here we present the complete mitochondrial genome of the hard clam Meretrix meretrix (Bivalvia: Veneridae). The entire mitochondrial genome (mitogenome) sequence of M. meretrix is 19,826 bp in length, and contains 37 genes including 12 protein-coding genes, 2 ribosomal RNAs, and 23 tRNAs. All genes are encoded on the heavy strand. In contrast to the typical animal mitochondrial genome, it lacks the protein-coding gene ATP8, and has only one copy of the tRNA(Ser) gene, but three duplications of the tRNA(Gln), which is the first report among the present molluscan mtDNAs. We observed that the gene arrangement between M. meretrix and M. petechialis is same except one more tRNAGln gene in M. meretrix., and the sequence similarity is as high as 99%, indicating that M. petechialis and M. meretrix could be treated as a junior synonym of M. meretrix. Maximum Likelihood and Bayeslan analysis of 12 concatenated protein-coding amino acid sequences place the Unionidae as a sister group to other bivalves, which reflects the general opinion that the Unionidae deverged very early in Bivalvia evolution.
authors.affiliation: The Key Laboratory of Marine Fishery Molecular Biology of Liaoning Province, Liaoning Ocean and Fisheries Science Research Institute, 50 Heishijiao Street, Dalian 116023, China. hechongbo@hotmail.com
authors.forename: Chong-Bo
authors.initials: CB
authors.lastname: He
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Xiang-Gang
authors.initials: XG
authors.lastname: Gao
authors.forename: Wen-Tao
authors.initials: WT
authors.lastname: Song
authors.forename: Hong-Jun
authors.initials: HJ
authors.lastname: Li
authors.forename: Yun-Feng
authors.initials: YF
authors.lastname: Li
authors.forename: Wei-Dong
authors.initials: WD
authors.lastname: Liu
authors.forename: Hao
authors.initials: H
authors.lastname: Su
mesh_terms: D000818:Animals; D049872:Bivalvia / Q000145:classification / Q000235:genetics*; D003062:Codon; D004272:DNA, Mitochondrial / Q000032:analysis* / Q000235:genetics; D023061:Gene Order; D054629:Genome, Mitochondrial; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D003062:Codon; D004272:DNA, Mitochondrial