Comparative analysis of mitochondrial genomes of Pleuronectidae (Pleuronectiformes) in the seas around the Korean Peninsula

Abstract

The blackfin flounder (Glyptocephalus stelleri) is a cold-water fish species inhabiting the East and South Seas of Korea. G. stelleri is mainly caught in the East Sea, Korea, and is a target species of the Fish Stock Rebuilding Plan. Also, the blackfin flounders account for up to 82% of all flounders caught in the East Sea, Korea. To understand the molecular evolution of the blackfin flounder, we sequenced the complete mitogenome and compared analysis of three species of Pleuronectidae (Acanthopsetta nadeshnyi, Pseudopleuronectes herzensteini, and Microstomus achne) that inhabit the seas around the Korean Peninsula. The mitogenome nucleotide sequences of G. stelleri were 17,142 bp in length and contained 37 genes (13 protein-coding genes, two rRNA genes, and 22 tRNA genes) and one noncoding region. The four species of Pleuronectidae had similar mitochondrial DNA genome structure, nucleotide composition, and gene arrangement, but there was a difference in the overlapped length of ND5 and ND6 genes (G. stelleri: 38 bp vs. the other species: 4 bp). Additionally, the control region did not contain motif and tandem repeat units. In the four species of Pleuronectidae, the mitogenome nucleotide sequence differed more in the control region than in the protein-coding gene region, and the difference in the nucleotide sequence of the protein-coding gene region between to be 0 to 11% on average. As a result of analyzing the molecular phylogenetic relationship using the mitogenome, four species of Pleuronectidae were clustered into two clades (Clade1: G. stelleri and M. achne; Clade2: A. nadeshnyi and P. herzensteini). This study is expected to contribute to the phylogenetic studies and understanding of evolutionary patterns of Pleuronectidae species inhabiting the seas around the Korean Peninsula.