小尾寒羊LHR基因组织表达、多态性及其与产羔性状的关联分析

Analysis of Tissue Expression, Polymorphism of LHR Gene and Its Association with Litter Size in Small Tail Han Sheep

为了揭示LHR基因在小尾寒羊下丘脑-垂体-卵巢轴(hypothalamic-pituitary-ovarian axis,HPOA)中的表达规律、多态性及其与产羔数的关系,深入了解其对小尾寒羊产羔性状的作用。本研究采用实时荧光定量PCR技术对6只小尾寒羊(FecB++型单、多羔母羊各3只)的生殖及脑组织中LHR基因的表达谱进行分析,同时采用Sequenom MassARRAY~?SNP技术对380只小尾寒羊和380只其他品种绵羊(小尾寒羊、滩羊、苏尼特羊、策勒黑羊、湖羊和草原型藏羊)LHR基因7个单核苷酸多态性位点(single nucleotide polymorphisms, SNPs)的多态性进行检测,并与小尾寒羊产羔数进行关联分析。结果显示,LHR基因在小尾寒羊大脑、下丘脑和卵巢中均有表达,其中在卵巢高表达。LHR基因在小尾寒羊多羔群体卵巢、大脑和下丘脑的表达均极显著高于单羔群体(P<0.01)。分型发现LHR基因中,4个SNPs位点的等位基因频率和基因型频率在多羔和单羔品种间差异均达到极显著水平(P<0.01);7个SNPs在大多数绵羊品种中均表现为中度多态(0.25<PIC<0.5);卡方适合性检验表明,7个SNPs在大多数绵羊品种中均处于Hardy-Weinberg平衡状态(P>0.05);关联分析表明,LHR基因有1个SNP多态性与小尾寒羊各胎产羔数显著相关(P<0.05),2个SNPs多态性与小尾寒羊各胎产羔数呈极显著相关(P<0.01)。本研究发现,LHR基因的3个SNPs位点的多态性与小尾寒羊产羔性状存在一定程度相关,暗示其可能参与小尾寒羊多羔性状调控。

This study was conducted to evaluate the expression patterns and polymorphisms of LHR gene in the hypothalamic-pituitary-ovarian axis (HPOA) and its association with litter size in Small Tail Han sheep, and further understand its effect on lambing traits of Small Tail Han sheep. The real-time fluorescence quantitative PCR (qPCR) method was used to detect the expression of the LHR gene in reproductive and brain tissues of 6 Small Tail Han sheep (3 polytocous and 3 monotocous ewes from the FecB ++ genotype) in this study. The 380 Small Tail Han sheep and total 380 sheep for Small Tail Han sheep, Tan, Sunite, Cele Black, Hu and Prairie Tibetan sheep were selected, and Sequenom MassARRAY SNP assay was applied to detect the polymorphism of 7 single nucleotide polymorphism sites (SNPs) of LHR gene. Then the association between LHR and litter size was analyzed in Small Tail Han sheep. The results showed that LHR gene was expressed in the brain, hypothalamus and ovary tissues, and highly expressed in ovary. The expression of LHR gene in ovary, brain and hypothalamus of polytocous Small Tail Han ewes was extremely significant higher than that of monotocous ewes ( P <0.01). The genotype frequencies and allele frequencies of the 4 SNPs were extremely significantly different between monotocous and polytocous sheep breeds ( P <0.01). Population genetic analysis indicated that 7 SNPs showed moderate polymorphism in most sheep breeds (0.25< PIC <0.5);The result of chi-square test showed that 7 SNPs were in Hardy-Weinberg equilibrium in most sheep breeds ( P >0.05). Association analysis showed that the polymorphism of one SNP in the LHR gene were significantly correlated with litter size in Small Tail Han sheep ( P <0.05), and the polymorphism of 2 SNPs were extremely significantly correlated with litter size in Small Tail Han sheep ( P <0.01). The preliminary results of this study showed that there was a correlation between the polymorphisms of 3 SNPs of LHR gene and litter size in Small Tail Han sheep, and the LHR gene may be involved in the regulation of prolificacy in Small Tail Han sheep.