The complete mitochondrial genome of the Tibetan fox (Vulpes ferrilata) and implications for the phylogeny of Canidae.

Canidae is a family of carnivores comprises about 36 extant species that have been defined as three distinct monophyletic groups based on multi-gene data sets. The Tibetan fox (Vulpes ferrilata) is a member of the family Canidae that is endemic to the Tibetan Plateau and has seldom been in the focus of phylogenetic analyses. To clarify the phylogenic relationship of V. ferrilata between other canids, we sequenced the mitochondrial genome and firstly attempted to clarify the relative phylogenetic position of V. ferrilata in canids using the complete mitochondrial genome data. The mitochondrial genome of the Tibetan fox was 16,667 bp, including 37 genes (13 protein-coding genes, 2 rRNA, and 22 tRNA) and a control region. A comparison analysis among the sequenced data of canids indicated that they shared a similar arrangement, codon usage, and other aspects. A phylogenetic analysis on the basis of the nearly complete mtDNA genomes of canids agreed with three monophyletic clades, and the Tibetan fox was highly supported as a sister group of the corsac fox within Vulpes. The estimation of the divergence time suggested a recent split between the Tibetan fox and the corsac fox and rapid evolution in canids. There was no genetic evidence for positive selection related to high-altitude adaption for the Tibetan fox in mtDNA and following studies should pay more attention to the detection of positive signals in nuclear genes involved in energy and oxygen metabolisms.