绵羊MKRN3基因多态性与产羔数的关联分析

Polymorphism of Sheep MKRN3 Gene and Its Association with Litter Size

本实验旨在探究绵羊MKRN3基因g.275981C>T与g.276999C>T位点多态性与绵羊产羔数之间的关系,以期为绵羊高繁殖力分子育种提供新的遗传标记。利用全基因组重测序结合Sequenom MassARRAY~?SNP技术对常年发情绵羊品种(小尾寒羊、策勒黑羊和湖羊)和季节性发情绵羊品种(滩羊、苏尼特羊和草原型藏羊)MKRN3基因2个多态位点多态性进行检测,并与小尾寒羊产羔数进行关联分析。结果表明:MKRN3基因g.275981C>T位点与g.276999C>T位点均存在3种基因型;g.276999C>T位点基因型频率和等位基因频率在2种发情模式绵羊品种间差异均达到极显著水平(P<0.01);g.275981C>T位点在6个绵羊品种中均表现为低度多态(PIC<0.25),g.276999C>T位点在6个绵羊品种中均表现为中度多态(0.25<PIC<0.5);g.275981C>T位点在苏尼特羊和策勒黑羊中均处于哈代温伯格平衡状态(P>0.05),g.276999C>T位点在6个绵羊品种中均处于哈代温伯格平衡状态;关联分析表明,g.275981C>T和g.276999C>T位点不同基因型与小尾寒羊第1、2、3胎产羔数均无显著关联。可见,MKRN3基因2个多态位点均不适合用于小尾寒羊产羔数选育。

To elucidate the association between MKRN3 gene polymorphism and litter size in sheep.Year-round estrous sheep breeds(Small Tail Han,Cele Black and Hu sheep)and seasonal estrous sheep breeds(Tan,Sunite and Prairie Tibetan sheep)were selected and Sequenom MassARRAY?SNP assay was applied to genotype g.275981C>T and g.276999C>T loci of MKRN3 gene.Then the association was analyzed between MKRN3 and litter size in Small Tail Han sheep.The result of genotyping showed that three genotypes were found at g.275981C>T and g.276999C>T loci in both year-round estrous and seasonal estrous sheep,both genotype frequency and allele frequency were very significantly different between year-round estrous and seasonal estrous sheep(P<0.01)in g.276999C>T locus of MKRN3 gene.Population genetic analysis showed that the g.275981C>T locus was at low polymorphism(PIC<0.25)in all sheep breeds;the g.276999C>T locus was at moderate polymorphism(0.25<PIC<0.5)in all sheep breeds.Theχ2 test indicated that the g.275981C>T locus of Sunite and Cele Black sheep was under Hardy-Weinberg equilibrium(P>0.05);the g.276999C>T locus of all sheep breeds was under Hardy-Weinberg equilibrium(P>0.05).Association analysis indicated that the polymorphism of g.275981C>T and g.276999C>T had no correlation with the litter size of the first,second or third parity in Small Tail Han sheep(P>0.05).Polymorphism of the 2 SNPs of MKRN3 gene had no significant effect on litter size of Small Tail Han sheep.