The complete mitochondrial genome of Indian gaur, Bos gaurus and its phylogenetic implications

Abstract

the gaur is the largest extant cattle species and distributed across South and Southeast Asia. Around 85% of its current global population resides in India, however there has been a gradual decrease in the gaur population over the last two decades due to various anthropogenic activities. Mitochondrial genome is considered as an important tool for species identification and monitoring the populations of conservation concern and therefore it becomes an obligation to sequence the mitochondrial genome of Indian gaur. We report here for the first time 16,345 bp mitochondrial genome of four Indian gaur sequenced using two different approaches. Mitochondrial genome consisted of 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, and a control region. Among the 37 genes, 28 were positioned on the H-strand and 9 were positioned on the L-strand. The overall base composition appeared to be 33.5% A, 27.2% T, 25.9% C and 13.4% G, which yielded a higher AT content. The phylogenetic analysis using complete mitochondrial genome sequences unambiguously suggested that gaur is the maternal ancestor of domestic mithun. Moreover, it also clearly distinguished the three sub species of B. gaurus i.e. B. gaurus gaurus, B. gaurus readei and B. gaurus hubbacki. Among the three sub species, B. gaurus gaurus was genetically closer to B. gaurus readei as compared to B. gaurus hubbacki. The findings of our study provide an insight into the genetic structure and evolutionary history of indian gaur. The gaur, Bos gaurus also known as "Indian bison" is the largest living wild cattle species belonging to the family Bovidae 1. The historical distribution of gaur ranged throughout much of the mainland South and Southeast Asia. But, currently it occurs in a few Asian countries such as Bangladesh,

Complete mitochondrial genome sequence of Bos frontalis (Gayal) from Bangladesh

“…4). Similar trend has frequently been observed among the previously reported Bos species [11][12][13][14][15].…”

“…The putative control region of the mitochondrial genome is located between the tRNA-P and tRNA-F consisting of 921 bp in length. Such similarity has also been observed in other closely related bovine species including Indian Mithun and B.gaurus [11][12].…”

“…6). Generally, such abnormal tRNA structures have been noticed in mammals including previously reported Indian gaur and Mithun [11,12,18]. Besides the standard Watson-Crick base pairs, a total of 9 unmatched base pairs are detected in these tRNAs (Fig.…”

Assembling mitogenome of Himalayan Black Bear (U. t. laniger) from low depth reads and its application in drawing phylogenetic inferences

“…In contrast, revolution in NGS technology has made considerable decrease in cost and increase in throughput (millions of short sequencing reads) and accuracy 17 , 18 . Several studies have demonstrated the application of NGS in drawing the phylogenetic inferences, genome organization and comparative assessment among the sympatric species by mapping and assembly the complete mitogenomes from low depth sequencing reads 19 – 21 .…”

“…(1234567890) Scientific Reports | (2021) 11:730 | https://doi.org/10.1038/s41598-020-76872-y www.nature.com/scientificreports/ decrease in cost and increase in throughput (millions of short sequencing reads) and accuracy 17,18 . Several studies have demonstrated the application of NGS in drawing the phylogenetic inferences, genome organization and comparative assessment among the sympatric species by mapping and assembly the complete mitogenomes from low depth sequencing reads [19][20][21] . Therefore, to overcome the unwieldy process of conventional sanger sequencing, we assembled the complete mitogenome directly from low depth NGS reads following a modified approach of mitochondrial baiting and mapping reported earlier by Hahn et al 22 .…”