Y-CHROMOSOMAL DIVERSITY ON INDIGENOUS SHEEP (OVIS ARIES) BREEDS IN NEPAL: COMPARISON WITH DOMESTIC AND WILD SHEEP

Abstract

Studies are limited in the Asian region to separate out the male-specific contribution specifically during breed development in domestic animals. The ancestral origin and genetic diversity of the Nepalese sheep population was investigated in four Nepalese sheep breeds (n=50 rams) and 11 Argali (O. ammon byth) sampled in the northwestern China near Nepal using Y-chromosome microsatellites and SNPs variation in SRY 5’ promoter gene. In the present study, Nepalese sheep as well as Argali, wild species found in northwestern China, showed the paternal monomorphism. Nepalese sheep shared the haplotype which most likely corresponds with defined haplotype HY_6. This haplotype includes mouflons and high percentage of domestic sheep. Nepalese sheep and speculated ancestor population, Argali population clustered separately revealed that there is no introgression from any of the extant wild populations to today’s sheep population. Paternal monomorphism in Nepalese male sheep might be due to an exaggerated reduction in male effective population size; however, the reason for monomorphism in case of Argali is not clear. For latter, further research with inclusion of more Y-chromosome markers are warranted for rigid conclusion.