High gene lfows promote close genetic relationship among ifne-wool sheep populations (Ovis aries) in China

摘要

The aim of our present study was to construct genetic structure and relationships among Chinese ifne-wool sheep breeds. 46 individuals from 25 breeds or strains were genotyped based on the IluminaOvine 50K SNP array. Meanwhile, genetic variations among 482 individuals from 9 populations were genotyped with 10 microsatelites. In this study, we found high genetic polymorphisms for the microsatelites, while 7 loci in the Chinese superifne Merino strain (Xinjiang types) (CMS) and 5 loci in Gansu alpine superifne-wool sheep strain (GSS) groups were found deviated from Hardy-Weinberg equilibrium (HWE). Genetic driftFST=0.019 (P<0.001) and high gene lfows were detected in al the 7 ifne-wool sheep populations. Phylogenetic analysis showed ifne-wool sheep populations were clustered in a group independent from the Chinese indigenous breeds such that the 7 ifne-wool sheep clustered distinct from Liangshan semiifne-wool sheep (LS) and Hu sheep (HY) relfected by different population differentiation analyses. Overal, our ifndings suggested that al ifne-wool sheep populations have close genetic relationship, which is consistent with their breeding progress. These populations, therefore, can be regarded as open-breeding populations with high levels of gene lfows. Furthermore, the two superifne-wool strains,viz., CMS and GSS, might be formed by strong artiifcial selection and with frequent introduction of Australian Merino. Our results can assist in breeding of superifne-wool sheep and provide guidance for the cultivation of new ifne-wool sheep breeds with different breeding objectives.