The complete mitochondrial genome of Microtus fortis calamorum (Arvicolinae, Rodentia) and its phylogenetic analysis

Microtus fortis is a special resource of rodent in China. It is a promising experimental animal model for the study on the mechanism of Schistosome japonicum resistance. The first complete mitochondrial genome sequence for Microtus fortis calamorum, a subspecies of M. fortis (Arvicolinae, Rodentia), was reported in this study. The mitochondrial genome sequence of M. f. calamorum (Genbank: JF261175) showed a typical vertebrate pattern with 13 protein coding genes, 2 ribosomal RNAs, 22 transfer RNAs and one major noncoding region (CR region).The extended termination associated sequences (ETAS-1 and ETAS-2) and conserved sequence block 1 (CSB-1) were found in the CR region. The putative origin of replication for the light strand (OL) of M. f. calamorum was 35 bp long and showed high conservation in stem and adjacent sequences, but the difference existed in the loop region among three species of genus Microtus. In order to investigate the phylogenetic position of M. f. calamorum, the phylogenetic trees (Maximum likelihood and Bayesian methods) were constructed based on 12 protein-coding genes (except for ND6 gene) on H strand from 16 rodent species. M. f. calamorum was classified into genus Microtus, Arvcicolinae for the highly phylogenetic relationship with Microtus kikuchii (Taiwan vole). Further phylogenetic analysis results based on the cytochrome b gene ranged from M. f. calamorum to one of the subspecies of M. fortis, which formed a sister group of Microtus middendorfii in the genus Microtus.

The organization of the M. f. calamorum mitochondrial genome. The tRNAs were denoted using single letter amino acid code. The protein coding genes were indicated as follows: ND1-6, NADH dehydrogenase subunits 1–6; COX1–3, cytochrome c oxidase subunits 1–3; ATP6 and ATP8, ATPase subunits 6 and 8; Cyt b, Cytochrome b; and CR, control region.Figure optionsDownload high-quality image (117 K)Download as PowerPoint slideHighlights
► The first mitochondrial genome of M. f. calamorum was reported in this study.
► The mitochondrial genome of M. f. calamorum showed a typical vertebrate pattern.
► M. f. calamorum show highly phylogenetic relationship with Microtus kikuchii.
► M. f. calamorum formed a sister group with Microtus middendorfii in the genus Microtus.