SIX1基因表达及其多态性与绵羊季节性繁殖和产羔数的关联分析

Expression and Polymorphism of Sheep SIX1 Gene and Their Association with Seasonal Reproduction and Litter Size

为探究繁殖组织中SIX1基因的表达水平及其多态性与绵羊季节性繁殖和产羔数之间的关系,本实验通过实时荧光定量PCR(qPCR)研究SIX1基因在不同产羔数(单羔组和多羔组)小尾寒羊卵巢、子宫体、输卵管组织中的表达情况,同时利用Sequenom MassARRAY?SNP技术检测多羔品种(小尾寒羊、湖羊、策勒黑羊共560只)和单羔品种(滩羊、苏尼特羊、草地型藏羊共204只)中SIX1基因g.69738971 T>G的多态性,并与其中有产羔数记录的380只小尾寒羊产羔数进行关联分析。结果表明:SIX1基因在小尾寒羊卵巢、子宫体、输卵管组织中均表达,且单羔组的子宫体中SIX1基因表达量显著高于多羔组(P<0.05);分型结果表明,SIX1基因g.69738971 T>G位点共存在TT、GT和GG 3种基因型,且基因型频率和等位基因频率在单、多羔品种(即高、低繁殖性能的母羊)间差异均极显著(P<0.01);卡方适合性检验表明,该位点在6个绵羊品种中均处于Hardy-Weinberg平衡状态(P>0.05);该位点多态性与小尾寒羊第1、2及第3胎产羔数均显著相关(P<0.05),即野生型(TT)各胎产羔数均显著高于突变型(GT和GG)。综上,SIX1基因表达与绵羊繁殖有关,该基因表达水平与绵羊产羔数可能存在一定程度的负相关,其g.69738971 T>G位点可作为控制绵羊季节性繁殖和产羔数性状的一个潜在分子标记位点。

To explore expression level of SIX1 gene in reproductive tissues and the association between polymorphism and seasonal reproduction,litter size in sheep,real-time fluorescent quantitative PCR(qPCR)was used to detect the expression of SIX1 gene in ovary,uterine body and oviduct of Small Tail Han sheep(STH)at different litter sizes(uniparous group and multiparous group).Sequenom MassARRAY SNP was applied for genotyping of g.69738971 T>G locus in SIX1 gene in multiparous(total 560 for STH,Hu and Cele black sheep)and uniparous(total 204 for Tan,Sunite and Prairie Tibetan sheep)sheep breeds,then the association was analyzed between SIX1 and litter size in STH.The results of qPCR showed that SIX1 gene was expressed in ovary,uterine body and oviduct in STH,and expression of SIX1 gene in uterine body of uniparous group was higher than that in multiparous group(P<0.05).The result of genotyping indicated that three genotypes(TT,GT and GG)were found at g.69738971 T>G locus of SIX1 gene,genotype frequency and allele frequency were extremely different between uniparous and multiparous sheep breeds(ewes of high and low reproductive capacity)(P<0.01).Theχ2 test indicated that g.69738971 T>G locus of SIX1 gene in six breeds was under Hardy-Weinberg equilibrium(P>0.05).Polymorphism of g.69738971 T>G had correlation with litter size of the first,second and third parity in STH(P<0.05),while litter size of TT genotype was higher than GT or GG genotype for each parity.Above results implied that SIX1 gene expression may be related to reproduction in sheep,there be a certain negative correlation between the expression level of SIX1 and litter size in sheep,the g.69738971 T>G locus might be considered as a potential molecular marker which controls seasonal reproduction and litter size in sheep.