Sequencing and characterization of mitochondrial DNA genome for Brama japonica (Perciformes: Bramidae) with phylogenetic consideration

Abstract

In this study, the complete mitochondrial genome sequence of Brama japonica is isolated and characterized by PCR and primer-walking sequencing techniques. The complete DNA is 17,009 bp in length and contained 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes and a long putative control region. The gene organization and nucleotide composition are identical to those of other Bramidae fishes. In contrast, the 12S rRNA gene contains a big poly C structure which is larger than those from other Bramidae species. Of 37 genes, twenty-eight are encoded by heavy strand, while nine are encoded by light strand. Among the 13 protein-coding genes, twelve employ ATG as start codon, while only one (COI) utilizes GTG as start codon. The terminal associated sequence (TAS), the central and conserved sequence block (CSB-E and CSB-D) and a variable domain (CSB-1, CSB-2 and CSB-3) are identified in the control region, while the typical central conserved CSB-F is not detected. From the phylogenetic tree, we find that B. japonica, together with other five Bramidae species form a monophyletic group among 24 species. This work provides a set of useful data for studies on population genetic diversity and molecular evolution in Bramidae fish species.