公猪7号染色体繁殖性状QTL的精细定位和位置候选基因MEA1的鉴别研究  

Fine Mapping of QTL and Identification of MEA1 as a Positional Candidate Gene Affecting Boar Reproduction Traits on SSC7

作　　者：赵科伟 赵雪艳[1] 张志燕[1] 洪渊[1] 范寅[1] 任军[1] 幸宇云[1] 

机构地区：[1]江西农业大学动物生物技术国家重点实验室培育基地,南昌330045

出　　处：《畜牧兽医学报》2014年第3期363-374,共12页ACTA VETERINARIA ET ZOOTECHNICA SINICA

基　　金：国家自然科学基金项目(31100891)

摘　　要：本研究旨在精细定位公猪7号染色体(SSC7)影响附睾重和血浆睾酮浓度的数量性状位点(QTL),鉴别影响公猪繁殖性状的位置候选基因。以205头白色杜洛克×二花脸资源家系F2公猪群体为研究材料,在初步定位的QTL区间内增加14个SNPs对该群体进行扫描以精细定位QTL。在精细定位QTL区间内筛选雄性增强抗原1(MEA1)为位置候选基因,采用标准关联分析和F-drop检验分析该基因的多态位点与公猪繁殖性状的关联性,通过实时定量PCR(RT-PCR)和差异表达分析其表达情况。结果表明:①影响附睾重和血浆睾酮浓度的QTL置信区间显著缩小。②MEA1基因的5个SNPs与公猪附睾重、血浆睾酮浓度和射精量极显著或显著相关(P<0.01或P<0.05);单倍型与表型关联性分析显示,G-C-C-G-C单倍型与左、右侧附睾重极显著相关(P<0.01),A-C-C-G-G单倍型与左、右侧附睾重显著相关(P<0.05);F-drop分析显示,g.-1168A>G和g.1115A>G位点可能为影响公猪血浆睾酮浓度的主效突变位点(QTN)或与QTN紧密连锁;差异表达分析表明,附睾重与MEA1在附睾中的表达量成负相关(相关系数为-0.300,P=0.1);MEA1在成年公猪的18种组织中均有表达。本研究通过精细定位缩小了7号染色体影响公猪附睾重和血浆睾酮浓度的QTL置信区间;同时发现MEA1基因与公猪附睾重、血浆睾酮浓度和射精量显著相关,其中g.-1168A>G和g.1115A>G位点可能是影响公猪血浆睾酮浓度的QTN或与QTN紧密连锁,这2个位点可作为选育性欲较强公猪的分子标记。This aim of this study was to fine map the QTL affecting boar epididymal weight and serum testosterone concentration on SSC7and to identify the positional candidate genes affecting boar reproduction traits.The materials used in this study were 205F2boars from a White Duroc× Erhualian resource population.For fine mapping the QTL affecting epididymal weight,14SNPs in the region preliminarily mapped were increased as markers to scan the boar population. Male-enhanced antigen 1(MEA1)was chosen as a positional candidate gene in the fine mapping region.Association and F-drop analyses were implemented to reveal the relationship between MEA1polymorphisms and boar reproduction traits.RT-PCR and differential expression assayswere used to detect the MEA1expression.The results showed that:①Fine mapping analyses revealed that the QTL region affecting epididymal weight and serum testosterone concentration was significantly narrowed.② Association analyses revealed that five SNPs of MEA1were extremely significantly or significantly associated with boar epididymal weight,serum testosterone concentration and semen volume(P<0.01or P<0.05).G-C-C-G-C haplotype was extremely significantly associated with boar left and right epididymal weight(P<0.01),and A-C-C-G-G haplotype was significantly associated with boar left and right epididymal weight(P<0.05).F-drop test showed that g.-1168A>G and g.1115A>G could be quantitative trait nucleotides(QTN)or be complete linkage disequilibrium with QTN affecting testosterone concentration.Differential expression analysis showed that epididymal weight had negative relationship with MEA1expression level in this tissue(r2=-0.300,P=0.1).qRT-PCR assay detected the expression of MEA1gene in all 18selected tissues of a mature boar.QTL regions affecting epididymal weight and serum testosterone concentration were narrowed through fine mapping.Significant association was found between MEA1gene and boar epididymal weight,serum testosterone concentration and semen volume.g.-1168A>G and g.1115A>G of MEA1co

关 键 词：公猪 繁殖性状 数量性状位点 精细定位 雄性增强抗原1 

分 类 号：S828[农业科学—畜牧学]