Mitochondrial DNA diversity and origin of Bos frontalis.

摘要

Bos frontalis is an enigmatic bovine species found in selected regions of Myanmar, Bangladesh, China, Thailand, Bhutan and India. Though there are conflicting hypotheses regarding its origin, the most widely held view is that Bos frontalis originated from direct domestication of Bos gaurus (gaur). To study this, we analysed mtDNA control region and cytochrome b gene sequences of 41 B. frontalis from China and India, together with the available sequences in the public databases. Bayesian inference revealed clustering of B. frontalis and B. gaurus sequences into two separate clades. Application of relaxed molecular clock to these clades shows that B. frontalis and B. gaurus diverge between 0.134 and 0.207 million years ago. This time estimate lies much outside the ~10,000-year-old history of animal domestication. Based on this finding, we argue that B. frontalis should be treated as a separate species/sub-species and not merely a domestic form of B. gaurus. Our study also highlights the gene flow between domestic cattle and B. frontalis population.