The complete mitogenome of blue sheep (Pseudois nayaur) from the Indian Himalayan Region and its comparative phylogenetic relationship with other related species

Abstract

The ‘Bharal’ or ‘Himalayan Blue Sheep’ (Pseudois nayaur) is endemic to the Himalayan and Tibetan Regions. There are gaps in the available database for the blue sheep mitogenome sequencing from the Indian region. We sequenced and characterized the whole mitogenome of one blue sheep individual using the Illumina Nova-seq 6000 platform, which was 16,718 bp in length. It included 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), two ribosomal RNA genes (rRNAs), and one non-coding control region (D loop). It was compared with other complete mitochondrial DNA sequences of blue sheep from the NCBI database. The whole mitogenome of blue sheep was found to be highly AT-biased (60%) and had a positive AT skew (0.121) and a negative GC skew (−0.341). In 13 PCGs of blue sheep, Leucine (15.58%) and tryptophan (2.72%) occurred most frequently. A typical secondary cloverleaf structure was observed for all tRNA genes except for tRNA-Ser, where a stable structure of dihydrouridine did not develop. The phylogenetic analysis showed Indian blue sheep population formed a separate clade with a genetic distance of 3.7 to 4.1% from the Chinese blue sheep population, suggesting it to be of a different lineage and genetically qualifies the status of distinct subspecies. The results of this study will help in further phylogenetic analysis of Indian blue sheep populations in the Western and Eastern Himalayan regions and in understanding lineage identification and evolution for further research.