猪IGF2R基因多态性及其遗传印记

【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。

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

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.