Control region translocation and a tRNA gene inversion in the mitogenome of Paraplagusia japonica (Pleuronectiformes: Cynoglossidae)

Paraplagusia japonica (Cynoglossidae, Soleoidei) is characterized by a bilaterally asymmetrical and a series of fringes on the lips on the ocular side. Here we report for the first time the mitogenome of this tongue sole, which is 16,694 bp in length, and the gene order has been reorganized. The tRNA-Gln gene translocated from the light strand (L-strand) to the heavy strand (H-strand), accompanied by tRNA-Ile gene shuffling. In addition, the putative control region translocated downstream to the place between the ND1 and the tRNA-Gln genes, leaving a 26-bp trace fragment in the original position. Nevertheless, the rest gene order is identical to that of the typical fish. In addition, it is the first report of the rare ATT as an initiation codon for ND3, and the ATP6 (-26) and ND5 (+26) are unusually shorter or longer than those in other flatfish. These data will provide useful information for better understanding the molecular mechanisms of gene reorganization in fish mitogenome.