绵羊PTGS2基因多态性与产羔数关联分析

Polymorphism of Sheep PTGS2 Gene and Its Association with Litter Size

研究旨在探索PTGS2基因g.65835868A>G和g.65834692A>G位点多态性与绵羊产羔数之间的关系,以期为绵羊多羔分子育种提供新的标记。利用Sequenom MassARRAY^■ SNP技术对PTGS2基因2个单核苷酸多态(Single nucleotide polymorphism,SNP)位点在多羔绵羊品种(小尾寒羊、策勒黑羊和湖羊)和单羔绵羊品种(滩羊、苏尼特羊、萨福克羊和草地型藏羊)中进行检测,并与小尾寒羊产羔数关联分析。分型结果表明,g.65835868A>G和g.65834692A>G位点基因型频率和等位基因频率在单、多羔绵羊品种间差异均不显著(P>0.05);群体遗传学分析表明,g.65835868A>G位点在滩羊、小尾寒羊和草地型藏羊3个群体中均表现为低度多态(PIC<0.25),在其余4个群体中表现为中度多态(0.25<PIC<0.5),g.65834692A>G位点在选择的7个群体中均表现为中度多态(0.25<PIC<0.5);卡方适合性检验结果表明,g.65835868A>G位点在小尾寒羊、苏尼特羊、湖羊、策勒黑羊、滩羊和草地型藏羊6个群体中均处于哈代-温伯格平衡状态(P>0.05),g.65834692A>G位点在选择的7个群体中均处于哈代-温伯格平衡状态(P>0.05);关联分析表明,g.65835868A>G位点多态性与小尾寒羊不同胎次产羔数之间并无显著相关(P>0.05),g.65834692A>G位点小尾寒羊第2胎GG型产羔数显著高于AA型(P<0.05)。综上,PTGS2基因与绵羊的繁殖性能有一定相关,且g.65834692A>G位点对绵羊产羔性状有调控作用,可作为多羔绵羊选育的辅助标记。

The aim of this study was to explore the polymorphism of the two loci(g.65835868A>G and g.65834692A>G)in the PTGS2 gene of sheep and its relationship with litter size,and to provide new markers for molecular breeding of prolificacy in sheep.The Sequenom MassARRAY^■ SNP assay was applied to genotype all sheep including polytocous(Small Tail Han sheep,Hu sheep,Cele Black sheep)and monotocous(Tan sheep,Sunite sheep,Suffolk sheep,Prairie Tibetan sheep)sheep breeds,then the association analyses were also conducted between the two loci in PTGS2 and litter size in Small Tail Han sheep.The genotyping results indicated that both genotype frequency and allele frequency at g.65835868A>G and g.65834692A>G were not significantly different between polytocous and monotocous sheep(P>0.05).Population genetic analysis showed that the g.65835868A>G locus had low polymorphism(PIC<0.25)in Tan sheep,Small Tail Han sheep and Prairie Tibetan sheep,and was at moderate polymorphism(0.25<PIC<0.5)in other sheep breeds,g.65834692A>G locus was at moderate polymorphism(0.25<PIC<0.5)in seven sheep breeds.The χ2 test indicated that the g.65835868A>G locus was under Hardy-Weinberg equilibrium(P>0.05)in Small Tail Han sheep,Sunite sheep,Hu sheep,Cele Black sheep,Tan sheep and Prairie Tibetan sheep,the g.65834692A>G locus was under Hardy-Weinberg equilibrium(P>0.05)in seven sheep breeds.Association analysis indicated that the polymorphism of g.65835868A>G had no correlation with the litter size in Small Tail Han sheep(P>0.05),the litter size of second parity in GG of g.65834692A>G was significantly higher than AA in Small Tail Han sheep(P>0.05).Therefore,PTGS2 gene is related to the reproduction of sheep,and the g.65834692A>G locus can be used as an auxiliary marker for breeding of polytocous sheep.