The Mitogenome of the Subarctic Octocoral Reveals a Putative tRNA Gene Nested within MutS.

We sequenced and analyzed the complete mitogenome of a Norwegian isolate of the octocoral using the Ion Torrent sequencing technology. The 18,790 bp circular mitochondrial genome was found to harbor the same set of 17 genes, which encode 14 protein subunits, two structural ribosomal RNAs and one tRNA, as reported in other octocorals. In addition, we detected a new tRNA-like gene sequence nested within the MutS protein coding region. This putative tRNA gene feature appears to be conserved among the octocorals but has not been reported previously. The mitogenome was also shown to harbor an optional gene (ORFA) that encodes a putative protein of 191 amino acids with unknown function. A mitogenome-based phylogenetic analysis, presented as a maximum likelihood tree, showed that clustered with high statistical confidence with two other species endemic to the Mediterranean Sea and the Southeast Pacific Ocean.