小尾寒羊GnRH基因组织表达、多态性及其与产羔性状关联分析

为揭示GnRH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多羔的作用,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)的生殖组织及脑组织中GnRH基因的表达谱进行分析,同时采用Sequenom MassARRAY~?SNP技术对380只小尾寒羊和共380只的小尾寒羊、滩羊、苏尼特羊、策勒黑羊、湖羊和草原型藏羊GnRH基因2个单核苷酸多态性位点(Single nucleotide polymorphisms,SNPs)的进行多态性检测,并与小尾寒羊产羔数进行关联分析。结果显示,GnRH基因在下丘脑、卵巢和子宫组织均有表达,其中在下丘脑高表达。在小尾寒羊多羔群体中,GnRH基因在卵巢、大脑、下丘脑、垂体的表达均极显著高于单羔群体(P0.01),暗示其可能参与了小尾寒羊多羔性状调控。分型发现GnRH基因2个位点基因型频率和等位基因频率在单、多羔品种间差异均不显著(P0.05)。关联分析表明,GnRH基因的2个SNPs位点的多态性与小尾寒羊各胎产羔数差异均不显著(P0.05);2个SNPs在所有绵羊品种中均表现为低度多态(PIC0.25);卡方适合性检验表明,2个SNPs在各个绵羊品种中均处于Hardy-Weinberg平衡状态(P0.05)。

Analysis on the tissue expression,polymorphism of GnRH gene and its association with prolificacy in Small Tail Han sheep

This study was undertaken to evaluate the expression patterns and polymorphisms of GnRH gene in the hypothalamic-pituitary-ovarian axis (HPOA) and its association with litter size in Small Tail Han sheep.The real-time fluorescence quantitative PCR (RT-qPCR) method was used to detect the expression of the GnRH gene in reproductive tissues and brain tissues of six Small Tail Han sheep (Three polytocous and three monotocous ewes from the FecB++ genotype) in this study.380 Small Tail Han sheep and 380 in total for Small Tail Han sheep,Tan,Sunite,Cele Black,Hu and Prairie Tibetan sheep were selected and Sequenom MassARRAY^® SNP assay was applied to genotype 2 single nucleotide polymorphism sites (SNPs) of GnRH gene.Then the association was analyzed between GnRH and litter size in Small Tail Han sheep.The results showed that GnRH gene was expressed in hypothalamus,ovary and uterus tissues and among which,GnRH was highly expressed in hypothalamus.The expression of GnRH gene in ovary,hypothalamus and uterus of polytocous Small Tail Han ewes was extremely significant higher (P<0.01) than that of monotocous ewes,and the GnRH gene might be involved in the regulation of multiple lambs in Small Tail Han sheep.From genotyping,we found the genotype frequencies and allele frequencies of the 2 SNPs were not significantly different between uniparous and multiparous sheep (P>0.05),association analysis showed that these 2 SNPs in GnRH gene were not significantly correlated with litter size in Small Tail Han sheep (P>0.05).The population genetic analysis indicated that 2 SNPs showed low polymorphism in all sheep breeds (PIC<0.25),and the result of chi-square test showed that 2 SNPs were at Hardy-Weinberg equilibrium in most sheep breeds (P>0.05).