The complete mitochondrial genome of the toad species Oreolalax xiangchengensis (Anura: Megophryidae) and phylogenetic analyses

Abstract

Oreolalax xiangchengensis is an alpine toad species of Megophryidae. We determined its complete mitogenome. The mitogenome has a length of 17,110 bp, containing 13 protein-coding genes, 2 rRNA genes, 23 tRNA genes, and a control region. It has a tandem duplication of tRNA-Met gene and a translocation of tRNA-Trp gene compared with typical vertebrate mitogenomes. Phylogenetic analyses based on the mitogenome sequences of 18 Megophryidae species were conducted to access phylogenetic assignments of O. xiangchengensis.

Keywords:

• Oreolalax xiangchengensis
• complete mitochondrial genome
• phylogenetic analyses

The toad genus Oreolalax belongs to Megophryidae, which is distributed in the southwestern China and northern Vietnam (Frost 2018). However, phylogenetic relationships of the genus were still in doubt (Wei et al. 2009). Oreolalax xiangchengensis is distributed in the eastern edge of Tibetan Plateau at the most west of the distribution range of Oreolalax, and it is an endemic species in China. The complete mitogenome would promote phylogenetic study of the species.

Here, we reported the complete mitogenome of O. xiangchengensis. One female O. xiangchengensis (topotypic specimen CIB20130642) was collected from Xiangcheng County, Sichuan Province, China, and was preserved in 95% ethanol. The specimen was preserved in Chengdu Institute of Biology, Chinese Academy of Sciences. Total DNA was extracted from the tissue using the DNeasy Tissue Kit (QIAGEN). The mitogenome was deposited in GenBank with the accession number MH727696. It has a length of 17,110 bp, containing 13 protein-coding genes, 2 rRNA genes, 23 tRNA genes, and a control region. The base composition of A + T (62.2%) was higher than G + C (37.8%), most common with vertebrates (Boore 1999). It has a tandem duplication of tRNA-Met gene and a translocation of tRNA-Trp gene from the ‘WANCY’ region to the location between tRNA-Pro gene and control region.

We used MEGA7 to construct the phylogenetic tree using the maximum-likelihood method (Figure 1) based on the mitogenome sequences of O. xiangchengensis of other 17 Megophryidae species and two outgroups according to the previous study (Frost et al. 2006). The results support that the genus Oreolalax is a monophyly and O. xiangchengensis are deeply clustered into this genus.

Figure 1. Maximum likelihood tree based on mitogenome sequences of 18 Megophryidae species and two outgroups. Numbers nodes are bootstrap supports.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Key Research and Development Program of China under Grant number [2017YFC0505202], Biodiversity Conservation Key Laboratory of Guizhou province Education Department, Guiyang College, Ocean Park Conservation Foundation, Hong Kong under Grant number [PR 1030001252], and the National Natural Science Foundation of China under Grant number [31201702].