Indigenous cattle of India belong to the species, Bos indicus and they possess various adaptability and production traits. However, little is known about the genetic diversity and origin of these breeds. To investigate the status, we sequenced and analyzed the whole mitochondrial DNA (mtDNA) of seven Indian cattle breeds. In total, 49 single-nucleotide variants (SNVs) were identified among the seven breeds analyzed. We observed a common synonymous SNV in the COII gene (m.7583G > A) of all the breeds studied. The phylogenetic analysis and genetic distance estimation showed the close genetic relationship among the Indian cattle breeds, whereas distinct genetic differences were observed between Bos indicus and Bos taurus cattle. Our results indicate a common ancestor for European Zwergzebu breed and South Indian cattle. The estimated divergence time demonstrated that the Bos indicus and Bos taurus cattle lineages diverged 0.92 million years ago. Our study also demonstrates that ancestors of present zebu breeds originated in South and North India separately ∼30,000 to 20,000 years ago. In conclusion, the identified genetic variants and results of the phylogenetic analysis may provide baseline information to develop appropriate strategies for management and conservation of Indian cattle breeds.
Keywords: genetic divergence; mitochondrial DNA; single-nucleotide variant.