中国地方绵羊群体TYRP1基因遗传变异研究

本研究旨在了解酪氨酸酶相关蛋白1（tyrosinase related protein 1，TYRP1）基因在中国地方绵羊群体内的遗传变异，以及TYRP1基因突变与不同毛色表型绵羊群体的相关性。通过直接测序法和PCR-RFLP技术对10个中国地方绵羊群体进行单核苷酸多态性（SNP）检测，利用Beagle、PLINK和POPGENE等软件对突变位点数据进行单倍型构建、连锁不平衡分析和遗传变异研究。突变位点检测结果表明，在绵羊TYRP1基因内识别了13个SNPs，其中位于TYRP1基因外显子上的10个SNPs位点，除个别位点在大尾寒羊、中国美利奴羊和岷县黑裘皮羊中没有发生突变外，其他突变位点在所有绵羊品种中均出现不同程度变异，说明中国地方绵羊群体具有较高的遗传多样性。单倍型分析结果表明，所有样本中共有42个单倍型，优势单倍型0000000000（245/918）、0100000001（91/918）在所有绵羊群体中均存在，除单倍型0101100000（93/918）在中国美利奴羊中没有出现，单倍型0001000001（69/918）在岷县黑裘皮羊、哈萨克羊群体中没有出现外，在其他群体中均存在。连锁分析结果表明，10个SNPs在所有样本中均存在2个连锁模块。群体遗传变异分析表明，中国地方绵羊群体具有较高水平的群体内遗传变异，各绵羊品种间存在明显的遗传分化模式，且各品种遗传关系与其品种传统分类结果基本一致。本研究为进一步研究TYRP1基因对绵羊毛色遗传性状的影响提供了参考依据。

Study on Genetic Variation of TYRP1 Gene in Chinese Indigenous Sheep Populations

This study was aimed to understand the population genetic variation and association relationship between the mutation sites of tyrosinase related protein 1(TYRP1) gene and different coat color phenotype in Chinese indigenous sheep populations.The directly sequencing and PCR-RFLP method were performed to identify single nucleotide polymorphisms (SNP) and genotype of TYRP1 gene,and then constructed haplotype,linkage disequilibrium analysis and genetic variation analysis were performed out by Beagle,PLINK and POPGENE softwares.The results showed that a total of 13 SNPs were identified in TYRP1 gene.10 SNPs of TYRP1 gene exons were chosen and used for genotyping in 10 sheep breeds.The results demonstrated that 10 sheep breeds presented variation at most mutation sites,except for some mutation sites had not polymorphisms in Large-tail Han sheep,China Merino sheep and Minxian Black-fur sheep.These results indicated that Chinese indigenous sheep populations had higher genetic diversity.The haplotypes analysis results indicated that a total of 42 haplotypes were detected in all sheep individuals,0000000000 (245/918) and 0100000001 (91/918) dominant haplotypes were detected in all sheep populations,except 0101100000 (93/918) was not detected in China Merino sheep,0001000001 (69/918) was not detected in China Merino sheep and Minxian Black-fur sheep,which were detected in other sheep populations.Linkage analysis results demonstrated that two block were detected in 10 SNPs of TYRP1 gene from all the sheep individuals.The genetic variation investigation indicated that Chinese sheep breeds had maintained a high level of within-population genetic differentiation,and the distinct genetic differentiation patterns and genetic relationships among the Chinese sheep breeds displayed a high consistency with the traditional classification.This study provided the theoretical basis for the further application of TYRP1 gene in coat color genetic traits of sheep.