Assessment of genetic variability among Indian sheep breeds using mitochondrial DNA cytochrome-b region

Abstract

Aim: The present study was conducted to estimate genetic distance, the phylogenetic relationship, and time of divergences using mitochondrial DNA (mtDNA). Materials and Methods: The total 216 unrelated samples were collected from native breeding tract of six Indian sheep breeds. The genomic DNA was isolated and screened for restriction enzyme polymorphisms for cytochrome b (Cyt-b) region of mtDNA with seven restriction enzymes. Results: The genetic distance among sheep breeds was ranging between 0.02833 and 0.0946. The phylogenetic analysis revealed that Malpura and Chokla were found closer relationship forming distinct cluster followed by Deccani individual were clustered with Nellore sheep, whereas Nali and Sonadi were distant to each other having separate cluster. Estimated divergence time among Indian sheep breeds were ranging about 1.41-4.73 million years ago (MYA) with an average of 3.063±0.27 MYA. It showed that Malpura and Sonadi sheep revealed highest divergence time as 4.73 MYA whereas Malpura and Chokla show the lowest as 1.41 MYA. Conclusion: In conclusion, the restriction fragment length polymorphisms-polymerase chain reaction (RFLP-PCR) of the Cyt-b region of mtDNA is suitable and cost effective tool for estimating the genetic variability, phylogenetic relationship, and time of divergence among Indian sheep breeds. These findings will help to formulate proper breeding strategies for conservation and utilization of sheep breeds.

Keywords

• genetics-diversity
• mitochondrial DNA
• restriction fragment length polymorphisms-polymerase
• chain reaction
• sheep breed