猪ZP4基因的SNP鉴定、选择压及其与产仔数的关联分析

Study on SNP Identification,Selective Pressure and Association Analysis with Litter Size for ZP4 Gene in Pigs

本试验旨在研究猪ZP4基因的SNP在群体中的选择压及其与产仔数的关联性。收集大白猪、长白猪、长大二元猪3个群体共计328头母猪的产仔数记录,利用直接测序法克隆ZP4基因中的SNP位点,采用广义显性模型分析ZP4基因SNP与产仔数的关联性。采用lositan软件,Tajima′s D检验和Fu and Li′s D检验来检测ZP4的选择压。结果发现,ZP4中共检测到27个SNPs,关联分析表明A268T在3个猪群体中均与总产仔数显著关联(P<0.05),A268T在长白猪和大白猪群体中与产活仔数显著关联(P<0.05),群体遗传学分析表明,T2950C位点受到了正选择作用,虽然该位点突变与产仔数关联不显著,但是T2950C与A268T存在紧密连锁。关联分析和选择压力分析说明ZP4基因可以作为猪产仔数的候选标记。

In this study, we investigated the single nucleotide polymorphisms （SNP） of ZP4 gene, its selective pressure and association with litter size in pigs. Totally, 328 sows and their litter size records were collected from Large White, Landrace and Landrace × Large White hybridization pig populations. Direct sequencing method was used to clone and identify the nucleotide mutation in ZP4. The generalized linear regression model was applied to investigate the correlation between ZP4 SNP and litter size. The lositan software, Tajima＇s testing and Fu and Lirs D testing were used to detect the selective pressure of ZP4. Our results demonstrated that 27 SNPs were detected in ZP4, and A268T was significantly correlated with number of total litter size in the 3 populations （P〈0. 05）. A268T was only significantly associated with number of born alive in Landrace and Large White pig pop- ulations （P〈0.05）. We also detected that T2950C was under positive selection and this mutation was linked with A268T. Our results suggested that A268T was a direct selection marker that could be used in pig marker assistant selection.