A study on genetic variation in Vizianagaram and macherla sheep of Andhra Pradesh using mitochondrial DNA

The aim of study was to assess genetic variation in two lesser-known sheep genotypes (Vizianagaram and Macherla) and Nellore breed of Andhra Pradesh using mtDNA D-loop region and their phylogenetic status. Blood samples were collected from five Vizianagaram and six Macherla sheep. Genomic DNA was isolated and 885 bp mitochondrial control region was amplified and sequenced. Metadata from Nellore and other Indian breeds were obtained from the NCBI database and a total of 341 sequences were aligned and trimmed to a final length of 721 bp. Polymorphism and divergence analysis revealed the existence of polymorphism among the three genotypes of Andhra Pradesh, suggesting that the three genotypes are distinct. The findings of gene flow and genetic differentiation estimates concluded the presence of high differentiation and moderate sub-structuring of three genotypes in Andhra Pradesh, similar to other sheep breeds in India. The phylogenetic analysis indicated that the haplotypes of Vizianagaram and Macherla sheep in the present study are in lineage-A along with the majority of other Indian sheep breeds. In Nellore sheep, out of 28 haplotypes, 26 were grouped in lineage A and 2 in lineage B. This separation may be due to the existing hypothesis that there may be two independent domestication events in India.