Characterization of the complete mitochondrial genome of Phodopus roborovskii (Rodentia: Cricetidae) and systematic implications for Cricetinae phylogenetics

Phodopus roborovskii (subfamily Cricetinae) is widely distributed in the northern arid regions of China. This study reports its complete mitochondrial genome (mitogenome) for the first time. The complete sequence was 16,273 bp long, including 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs, and 1 major noncoding region. The base composition and codon usage were described. The putative origin of replication for the light strand (OL) of P. roborovskii was approximately 45 bp long and was highly conserved in the stem-loop and adjacent sequences, but the starting sequence of replication varied between genera among Rodentia. We analyzed the three domains of the D-loop region, and the results indicated that the central domain had higher G + C content and lower A + T content than two peripheral domains. Phylogenetic analyses indicated high resolution in four main divergent clades using mitogenomes data within Cricetidae. Within Cricetinae clade, P. roborovskii was at basal position which was in line with previous researches, and it shared a common ancestor with other extant hamsters. This work validated previous molecular and karyotype researches using mitogenomes data, and provided a set of useful data on phylogeny and molecular evolution in Cricetidae species.