Mitochondrial genome of the Eurasian otter Lutra lutra (mammalia, carnivora, mustelidae)

We determined the complete mitochondrial genome of the Eurasian otter Lutra lutra, which is an endangered species in Korea. The circle genome (16,536 bp in size) consists of 13 protein-coding, 22 tRNA, and 2 rRNA genes, and a control region, as found in other metazoan animals. Out of the 37 genes, 28 are encoded on the H-strand, and the nine (ND6 and 8 tRNA genes) on the L-strand. Three overlaps among the 13 protein-coding genes were found: ATP8-ATP6, ND4L-ND4, and ND5-ND6. A control region (1090 bp) including the origin of H-strand replication (OH), TAS (a conserved motif TACAT-16bp-ATGTA) and CSB (CSB-1, CSB-2, and CSB-3) was observed between tRNA-Pro and tRNA-Phe genes, and O_L with 36 highly conserved nucleotides between tRNA-Asn (N) and tRNA-Cys (C) within a cluster of five tRNA genes (WANCY), as typically found in vertebrates. The other important characteristics of the L. lutra mitochondrial genome were described in detail. In addition, a maximum likelihood and Bayesian trees of 9 mustelid species and 1 outgroup were reconstructed based on the nucleotide sequences of 11 protein-coding genes excluding ATP8 and ND6. It showed that Lutrinae formed a monophyletic group with Mustelinae that is not monophyletic. Within the subfamily Lutrinae, L. lutra and Enhydra lutris were grouped together and then Lontra canadentis placed as a sister of the clade. The present result is the first complete mitochondrial genome sequence reported from the genus Lutra, and is applicable to molecular phylogenetic, phylogeographic, conservation biological studies for mustelid members. In particular, exploration of sequence variations of the control region may be helpful for analyzing interand intra-species variations in the genus Lutra.