Search

In the present study, the complete mitochondrial genome of the oval flounder Bothus myriaster was determined and a novel gene rearrangement was discovered. A striking finding was that eight genes encoded by the L-strand (ND6 and tRNA-Q, A, C, Y, S1, E, and P genes) were translocated to a position between tRNA-T and tRNA-F. Simultaneously, the original order of the rearranged genes Q-A-C-Y-S1-ND6-E-P was maintained. Thus, the genes with identical transcriptional polarities were clustered in the genome with one exception that tRNA-N gene is located in the original position. The other rearrangement was the H-strand-encoded tRNA-D that translocated from its typical location between COI and COII to a position between S1 and ND6. The Dimer-Mitogenome and Non-random Loss model (DMNL)was adopted to account for the novel rearrangement in B. myriaster mitogenome, which provides evidence to support the hypothesis of the DMNL model.

Cynoglossus zanzibarensis (Cynoglossidae, Soleoidei) is characterized by both eyes on the left side of the body. Here we report the mitogenome of this tonguesole for the first time, which is 16,569 bp in length, with gene order reorganized. The tRNA-Gln gene is translocated from the light strand (L-strand) to the heavy strand (H-strand), accompanied by shuffling of tRNA-Ile and tRNA-Met genes with a 160-bp intergenic spacer between tRNA-Gln and tRNA-Ile. The putative control region is translocated downstream to the place between the ND1 and the tRNA-Gln genes, leaving a 25-bp trace fragment in the original position. The rest of the gene arrangement is identical to that of the typical fish.