猪IGF2R基因多态性及其遗传印记

Studies on SNP and Genomic Imprinting of the IGF2R Gene in Swine

【目的】在猪IGF2R基因的外显子内寻找SNP,以SNP为遗传标记研究IGF2R基因的印记表达特征。【方法】选取3个品种243头瘦肉型商品猪为试验材料,以IGF2R基因为候选基因,通过PCR-SSCP对IGF2R基因多态性进行检测;选取IGF2R基因外显子48的SNP杂合子仔猪3头和成年猪1头,对脑、心脏、肝脏、脾、肾、肺、胃、胰、胸腺、膀胱、肌肉、舌、胎盘的组织器官mRNA产物分别进行RT-PCR-RFLP电泳和RT-PCR-SSCP电泳。【结果】IGF2R基因外显子48中有一个单核苷酸多态性位点,384位碱基由G突变为A,该位点为NspⅠ酶切位点;IGF2R的外显子48在3头仔猪和1头成年猪的主要组织器官仅表达母亲来源的等位基因。【结论】猪IGF2R基因呈母方表达、父方印记的遗传特征。

【Objective】 In this study,single nucleotide polymorphism （SNP） was found in IGF2R exons and used as marker to investigate the imprinting pattern of IGF2R in swine. 【Method】 Gene polymorphism of swine IGF2R was detected from 243 pigs of three breeds by PCR-SSCP. Imprinting patterns of IFG2R exon 48 were analyzed in organs of three heterozygous piglets and one hog by RT-PCR-RFLP/SSCP. 【Result】 One SNP（a G→A transition） was identified in exon 48 of IGF2R ,located at the 384th nucleotide （5→3）,forming a Nsp I restriction site. Maternal expression of IGF2R exon 48 was observed in the main organs of four heterozygous pigs. 【Conclusion】 IGF2R exon 48 was maternally expressed and paternally imprinted in most tissues of piglets and hogs.