Complete mitochondrial genome of the golden takin (Budorcas taxicolor bedfordi).

The complete mitochondrial genome sequence of Budorcas taxicolor bedfordi was 16 662-bp long, containing 13 protein-coding genes (PCGs), 22 tRNA genes, 2 rRNA genes and a control region. All of the PCGs begin with the typical ATN start codon. Stop codons TAA and AGA are present in the PCGs; exceptions are ND2, COIII, ND3 and ND4, which possess incomplete termination codon (T--). Secondary structure prediction of the 22 tRNA genes revealed the absence of the DHU arm in tRNASer(AGN).

Golden takin, Budorcas taxicolor bedfordi, is uniquely distributed in Qinling Mountains in China. It is classified as Vulnerable (VU) under International Union for the Conservation of Nature and Natural Resources (IUCN) (2008) criteria, and is a first-class national protected animal in China. The limited molecular data dampen the phylogenetic and evolution studies on B. t. bedfordi. Here, the complete mitochondrial genome of B. t. bedfordi has been reported with the general features. An illegal hunting B. t. bedfordi was collected by forest police in Qinling Mountains (33°47′N′, 107°42′E), Shaanxi, China. This specimen is stored in Shaanxi Key Laboratory for Animal Conservation (accession number LN13112). The mitochondrial genome was determined after PCR amplification, sequencing and annotation.

The complete mitochondrial genome of B. t. bedfordi is 16 662 bp in length and has been deposited in GenBank (accession no. KU361169). Its genes arrangement, order and orientation are identical to that of typical mammal mtDNA (Shen et al. 2012). There are 13 intergenic spacer regions, ranging in size from 1 to 7 bp (21 bp in total). Gene overlap involves 72 bp over seven locations. ATP8 and ATP6 have the longest overlap (40 bp). The overall base composition of the whole mitochondrial genome was A (33.9%), T (27.0%), C (26.3%) and G (12.8%), with an AT bias of 60.9%. The typical ATN (ATG or ATT) start codon is present in all of the 13 B. t. bedfordi PCGs. Open-reading frames of most B. t. bedfordi genes end with TAA or AGA, while ND2, COIII, ND3 and ND4 have the incomplete stop codon T––. All the tRNA genes that can fold into cloverleaf secondary structures except for the shortest gene tRNA (60 bp), in which the DHU arm has been replaced by a simple loop.

The A + T-rich region, which is located between srRNA and tRNA, is 1233 bp in length. There were 2 repeats of a short core sequence of alternating purines and pyrimidines and constituting a GYRCAT (Y = C/T, R = A/G) motif in the RS2 region of ETAS region. F, E, D, C, B-box, and CSB1-box elements (Douzery & Randi 1997; E Sbisa et al. 1997; Guo et al. 2015; Iyengar et al. 2006).

To further validate the mitogenome of B. t. bedfordi and research the phylogenetic relationships of Bovidae, the phylogenetic analyses were performed using MrBayes 3.1.2 (Ronquist & Huelsenbeck 2003) based on the whole mitogenome of B. t. bedfordi and the other 13 taxa that were retrieved from GenBank (KR011113, AF492351, KR059225, AP003429, JX312729, NC020708, AP003424, NC012694, NC021381, KF826487, NC001941, NC020633, AP003428) (Figure 1).

Figure 1.

The BI phylogenetic tree of the B. t. bedfordi brachycerus in this study and other 13 Artiodactyla speices based on whole mitogenome.