猪CD8B表达谱、基因多态性及其与血液免疫性状的关联分析  

Expression Profile and Polymorphism of CD8B Gene and Its Association with Blood Immune Traits in Pigs(Sus scrofa)

作　　者：许金根[1,2] 王重龙[2,3] 车传燕[1] 蔡治华[1] 李升和[1] 张勤[2] 

机构地区：[1]安徽科技学院动物科学学院,凤阳233100 [2]中国农业大学动物科技学院,北京100193 [3]安徽省农业科学院畜牧兽医研究所,合肥230031

出　　处：《农业生物技术学报》2016年第3期357-365,共9页Journal of Agricultural Biotechnology

基　　金：安徽科技学院引进人才项目(No.ZRC2014400);安徽科技学院兽医学重点学科经费项目(No.AKZDXK2015A04);国家生猪现代产业技术体系项目(No.CARS-36)

摘　　要：白细胞分化抗原8(cluster of differentiation 8,CD8)是主要表达在CD8+T细胞表面的共受体和信号转导分子。CD8B基因编码CD8蛋白的β链,在免疫应答中起着潜在的调节作用。为分析CD8B基因在猪(Sus scrofa)不同组织中的表达特征,并探究CD8B基因多态性对血液免疫性状的遗传效应,本研究利用q RT-PCR测定CD8B基因在大白猪7个组织中的表达量,并用PCR产物测序与限制性片段长度多态性(restriction fragment length polymorphism,RFLP)方法对382头大白猪、84头长白猪和90头松辽黑猪CD8B基因编码区进行SNPs检测,以及分析CD8B基因突变对大白猪外周血T淋巴细胞亚群和血常规指标的影响。结果表明,CD8B基因在脾脏中的m RNA表达量最高,然后依次是肺脏、胃、肝脏、肾脏、心脏和肌肉。CD8B基因外显子5处检测到1个错义突变(c.602G>A),在大白猪、长白猪和松辽黑猪群中均存在3种基因型(AA、AG和GG型),且3个猪种都是GG为优势基因型。统计分析显示,CD8B基因多态性与大白猪血液中的CD4+CD8-、CD4-CD8+、CD4+/CD8+、血红蛋白含量(hemoglobin,HGB)和红细胞压积(hematocrit,HCT)指标显著相关(P<0.05)。最小二乘分析表明,3种CD8B基因型个体具有不同的血液参数,其中GG型的CD4+CD8-指标显著高于AG型,AG型的CD4-CD8+指标显著高于GG和AA型,GG和AA型的CD4+/CD8+、HGB和HCT指标显著高于AG型(P<0.05)。因此,CD8B基因可能参与血液生理指标的调控,可作为影响猪免疫性状的重要功能候选基因。本研究为进一步揭示CD8B基因的生物学功能提供依据,也为猪的标记辅助抗病育种提供了基础资料。The cluster of differentiation 8（CD8） is a co-receptor and signal transduction molecule, which is mainly expressed on the surface of CD8^＋T cells. Because of the β chain of CD8 protein is encoded by the CD8 B gene, it plays a potential regulatory role in immune responses. The aim of this study was to analyze the expression profile of the CD8 B gene in different tissues of pigs（Sus scrofa）, and to reveal genetic effects of theCD8B gene polymorphisms on blood immune traits. The expression level of the CD8 B gene in 7 tissues of Large White pigs was quantified by q RT-PCR. Moreover, SNPs in the complete coding sequence of the CD8 B gene were screened by PCR product sequencing and restriction fragment length polymorphism（RFLP）methods in 382 Large White, 84 Landrace and 90 Songliao Black pigs, and effects of the CD8 B gene mutations on peripheral blood T lymphocyte subsets and hematological traits were further analyzed in the Large White samples. The results showed that the CD8 B m RNA preferentially expressed in spleen, followed by in lung, stomach, liver, kidney, heart and muscle. A missense mutation（c.602GA） was identified in exon5 of the CD8 B gene. Three genotypes（AA, AG and GG genotypes） were all detected in Large White,Landrace and Songliao Black populations, and GG was the predominant genotype in the 3 swine breeds.Statistical analysis showed that the CD8 B gene polymorphism was significantly associated with several blood immune parameters including CD4^＋CD8^-, CD4-CD8^＋, CD4^＋/CD8^＋, hemoglobin（HGB） and hematocrit（HCT） in Large White pigs（P〈0.05）. The least square analysis revealed that individuals with 3 CD8 B genotypes carried different blood indexes, and the CD4^＋CD8^-index of pigs with the GG genotype was significantly higher than those of the AG genotype, and the CD4-CD8^＋index of individuals with the AG genotype was significantly higher than those of GG and AA genotypes, and the CD4^＋/CD8^＋, HGB and HCT indexes of individuals with GG and AA genotypes

关 键 词：猪 白细胞分化抗原8B基因(CD8B) 基因表达 SNP 血液免疫指标 

分 类 号：S828[农业科学—畜牧学] S813[农业科学—畜牧兽医]