Complete mitochondrial genome of the Yunnanilus Sichuanensis and phylogenetic analysis

The complete mitochondrial genome of the Yunnanilus sichuanensis (Cypriniformes: Nemacheilinae) was first sequenced using the next-generation sequencing in this study. The mitogenome was 16,571 bp in length and contained 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes, 1 displacement loop (D-loop) locus, and an origin of replication on the light-strand (OL) region. Most of the genes were encoded on the heavy strand except ND6 and 8 tRNA genes encoded on the light strand. The mitogenome organization and gene order were similar to a typical vertebrate mitogeneome. The overall base composition was 26.96% A, 28.62% T, 25.75% C and 18.67% G, with 55.58% AT. Phylogenetic analysis based on the 13 protein-coding genes nucleotide sequences with two different methods (neighbour-joining and maximum likelihood analysis) showed that Y. sichuanensis was nearest to Y. jinxiensis, coming together into a branch, meanwhile together with Triplophysa venusta formed a sister group. This study enriched the data of the mitogenome of the genus Yunnanilus, and provide an important information for morphological classification of Nemacheilinae species and the study of biological origin.