Genetic variation of 5 SNPs of MC1R gene in Chinese indigenous sheep breeds.

ABSTRACT

The purpose of this study was to assess genetic diversity, genetic differentiation.relationship and population structure among 10 Chinese sheep populations using 5 single nucleotide polymorphisms (SNPs). in MC1R gene. The genetic diversity indices suggested that the intra-population variation levels of Chinese Merino and Large-tailed Han,breeds were lowest than Kazakh Fat-Rumped. Chinese sheep breeds have maintained a high intra-population variation levels (95.23%). The genetic differentiation patterns and genetic relationships among Chinese sheep breeds displayed a high consistency with the traditional classification. The cluster trees were constructed by UPMGA method. The results showed that Chinese indigenous sheep populations have distinct genetic differentiation. The inter-population variation levels in Chinese sheep populations indicated three geographically independent domestication events have occurred. The Bayesian cluster analyses also showed a reliable clustering pattern, which revealed three major clusters in.Chinese indigenous sheep populations (Mongolian group, Kazakh group and Tibetan group), except for Duolang and Minxian Black-fur. There were probably caused by different breeding history, geography isolation and different levels of inbreeding. The findings supported the related records in literature, ten sheep populations originated on different time stage from the primogenitor population and communicated genetically with each other in the process of natural and artificial selection, and in different ecological environment. It is concluded that Chinese indigenous sheep have higher genetic variation and diversity, genetic differentiation exist between Chinese sheep populations. The majority breeds are consistent with the geographical distribution and breed characteristic.