牛Wif1基因印记及甲基化调控印记的分子机制研究  

Genomic Imprinting and Methylation in Regulating Imprinting of Wif1 Gene in Cattle

作　　者：吴茜红[1] 张明月[1] 杨文志[1] 吴国江[1] 李世杰[1] 

机构地区：[1]河北农业大学生命科学学院,保定071000

出　　处：《畜牧兽医学报》2015年第8期1325-1332,共8页ACTA VETERINARIA ET ZOOTECHNICA SINICA

基　　金：国家自然科学基金(31372312);河北省自然基金项目(C2011204001)

摘　　要：为了研究Wif1基因在牛中的印记状态和调控印记的分子机制,本研究首先应用基于单核苷酸多态(SNP)的测序方法,分析了Wif1基因在牛组织中的印记状态,结果发现,Wif1基因在牛中的印记表现出组织特异性,在肺中为单等位基因表达,而在心、肝、脾、肾、肌肉和脂肪6个组织中为双等位基因表达。进一步应用亚硫酸氢盐测序法分析Wif1基因启动子区29个CpG位点在牛肺(单等位基因表达)和肝(双等位基因表达)组织中等位基因特异的甲基化状态,结果发现,在肺和肝中,两条亲本链间的甲基化水平无显著差异(P>0.05)。进一步分析每个CpG位点在肺和肝中亲本链间甲基化率差异,发现与双等位基因表达的肝相比,肺中存在8个亲本链间甲基化率差异显著的CpG位点,其中3个(第1、2和6)位于转录因子的结合位点上。由于单个CpG位点的甲基化变化会影响转录因子的结合,推测这3个CpG位点的甲基化可能参与调控Wif1基因的组织特异性印记。To study the imprinting status and the regulatory mechanism of Wif1 in cattle,the imprinting status of Wif1 gene was analyzed by sequencing method based on a single nucleotide polymorphism(SNP).The results showed that Wif1 gene exhibited monoallelic expressions in lung tissues,but biallelic expressions in heart,liver,spleen,kidney,muscle and subcutaneous fat tissues,suggesting that the imprinting of Wif1 was tissue-specific in cattle.To analyze the possible role of DNA methylation in regulating Wif1tissue-specific imprinting,the methylation status of29 CpG sites in Wif1 gene promoter region was analyzed in lungs(monoallelic expressed tissues)and livers(biallelic expressed tissue)by bisulfite sequencing.The results showed that the methylation levels between the 2parental strands exhibited no significant difference(P>0.05)neither in lung nor liver tissues.The difference of methylated rates of each CpG sites between 2parental chains in lungs and livers was further analyzed,and 8CpG sites exhibiting significant difference of methylation rate between parental chains were found in lungs compared to those in livers.Among them,CpG sites 1,2and 6were contained in the transcription factor biding site.Because the methylation changes of individual CpG sites can effect the binding of transcription factors,the methylation of 3CpG sites in Wif1 promoter region may be involved in the regulation of tissue-specific imprinting of cattle Wif1 gene.

关 键 词：牛 Wif1 印记状态 DNA甲基化状态 CpG位点 

分 类 号：S823[农业科学—畜牧学]