狼山鸡NLRC5基因启动子区SNP及其在先天免疫中的效应分析

SNPs of Promoter Region of NLRC5 Gene and Its Genetic Effect on Innate Immune Traits in Langshan Chicken Breeds

旨在通过检测狼山鸡NLRC5基因启动子区单核苷酸多态位点,确定不同基因型的遗传效应,并经过后代分离群体验证,以期筛选与先天免疫性状相关的遗传标记。本研究采用MALDI-TOF-MS技术对狼山鸡群体NLRC5基因启动子区SNPs位点进行扫描;同时测定部分免疫性状,分析不同基因型个体免疫性状的差异。结果发现,在g.628981处存在A/G突变,共AA、AG和GG 3种基因型,狼山鸡不同基因型免疫指标间存在显著差异,AA基因型个体的H/L值显著低于GG基因型个体,而胸腺指数、脾脏指数、淋巴细胞转化率和IgG含量均显著高于GG基因型个体(P<0.05);在F2代AA和GG两个分离群体中同样发现AA型个体各项性状值均优于GG型个体。结合NLRC5基因在胸腺与脾组织中转录水平的差异,表明AA基因型个体表现出较好的先天免疫性能,NLRC5基因g.628981(A/G)位点可作为先天免疫性状有效的遗传标记。

This study was conducted to detect single nucleotide polymorphisms（SNPs）in NLRC5 gene promoter region of Langshan chicken,and further determine genetic effects of different genotypes which were verified by progeny segregating group,aiming to develop genetic markers associated with innate immune traits.MALDI-TOF-MS method was applied to scan SNPs in NLRC5 gene promoter region;afterwards,some immune traits and their differences between individuals with different genotypes were analyzed.The SNP scanning results found A/G mutation at g.628981 site,along with 3genotypes,namely,AA,AG and GG.The immune indexes presented significant difference among individuals with different genotypes.The H/L value of individuals with AA genotype was significantly lower than that of individuals with GG genotype,but spleen index,thymus index,lymphocyte transformation rate and content of IgG were significantly higher than that of individuals with GG genotype（P〈0.05）;it was also found that the traits of individ-uals with AA genotype were better than that of individuals with GG genotype in F2 generation of AA and GG segregating groups.Collectively,combining with the transcription differences of NLRC5 gene in thymus and spleen tissues,our study indicate that birds with AA genotype show better performances of innate immunity and g.628981（A/G）site of NLRC5 gene can be used as an effective genetic marker of innate immune traits.