Mitochondrial DNA variation in indigenous sheep (Ovis aries) breeds of Nepal

N.A Gorkhali,J.L Han,Y.H Ma

doi:10.4038/tar.v26i4.8125

Abstract

Nepal borders India in the south and China in the north. Four distinct indigenous domestic sheep breeds, i.e. Bhyanglung in the alpine region, Baruwal in the high hills, Kage in the mid hills and Lampuchhre in the low lands are distributed in the country. In this study, the mitochondrial DNA control region of 111 sheep from these four breeds was directly sequenced to determine their genetic variations and phylogenetic relationships. High mitochondrial DNA diversity among these breeds was observed and all haplotypes were classified into three haplogroups (A to C). Among the four breeds, three residing in middle to high hills had all three haplogroups while Lampuchhre sheep in low land only carried haplogroups A and B. This study revealed that a south-western route of gene flow in sheep might have come from China to India via Nepal. It can be concluded that these indigenous sheep breeds have isolated breeding paths. Lack of crossbreeding among Nepalese sheep breeds is unique, and it is important for the decision making on utilization and conservation of Nepalese sheep genetic resources.

Highlights

Domestic sheep (Ovis aries) have played a significant role in the economy of small and marginal farmers, especially in developing countries, as they are a potential source of meat, wool, milk, hide and manure
The variable structure of control region of mitochondrial DNA (mtDNA) makes it possible to solve the problem of genetic polymorphism and origin, mainly because mtDNA displays a simple maternal inheritance without recombination and a relatively rapid evolution rate (Hiendleder et al, 1998b)
The mtDNA control region sequences from 111 Nepalese sheep samples sequenced in this study had four one-nucleotide insertions/deletions, all involving thymine nucleotide

Summary

Introduction

Domestic sheep (Ovis aries) have played a significant role in the economy of small and marginal farmers, especially in developing countries, as they are a potential source of meat, wool, milk, hide and manure. Following the variations in agro-ecological zones and climates, Nepalese sheep have evolved into four different breeds: Bhyanglung in the alpine region (3000 masl to 5000 masl), Baruwal in the high hills (2000 masl to 3000 masl), Kage in the middle hills (600 masl to 1500 masl) and Lampuchhre in the low lands (sea level to 600 masl). These breeds are phenotypically distinct from each other (Neopane et al, 2008). The objective of this study was to investigate the genetic diversity and structure of four Nepalese sheep breeds using mtDNA control region sequence variation

Objectives

Methods

Results

Conclusion