大梅组合中亲子代甲基化差异及其与生产性状的关系(英文)  

Differences of Cytosine Methylation in Parental Lines and Hybrid F_1 of Large White × Meishan and Their Effects on F_1 Performanc

作　　者：蒋曹德[1] 邓昌彦[1] 熊远著[1] 

机构地区：[1]华中农业大学动物科技学院农业部猪遗传育种重点实验室,武汉430070

出　　处：《农业生物技术学报》2005年第1期46-51,共6页Journal of Agricultural Biotechnology

基　　金：Supported by the State Key Basic Research and Development Plan(973)Project(No.TG2000016105)and the State High Science and Technology Developing Plan(863)Project(No.2001AA243031)of China.

摘　　要：为了探讨DNA甲基化对杂种优势的影响,采用了甲基化敏感随机扩增PCR技术(methylation-sensitiveAP-PCR,MS-AP-PCR),利用40条随机引物对大梅组合亲子代基因组DNA进行了扩增。结果:在RsaⅠ+HpaⅡ酶切扩增片段中,有19个位点在亲子代出现差异;在RsaⅠ+HpaⅡ酶切扩增片段中,有14个位点在亲子代出现差异。亲子代间甲基化状况可归纳为4种类型:(1)亲子代甲基化水平相同;(2)单亲与F1代甲基化水平相同;(3)同亲代相比,F1代发生甲基化;(4)同亲代相比,F1代去甲基化。5个甲基化变化位点对7个生产性状产生显著的影响(P<0.05)。通过对生产性状产生显著影响的片段序列分析发现,这些序列在GenBank中有同源序列(同源性高于87%);3个片段G+C%大于50;所有片段CpG岛观测值/期望值都大于0.6;而且,有一个片段含有G/C盒。表明:基因启动子区域CpG岛甲基化在亲子代出现差异;不同甲基化位点对杂种生产性状的作用方向不同,说明杂种优势的表现既与有些基因的表达有关,也与有些基因的表达抑制有关。In order to probe the effect of methylation on heterosis, methylation-sensitive AP-PCR technique was adopted to amplify pig genome DNA with 40 single arbitrary primers. The material involved parental lines and hybrid F1 of Large White × Meishan. Nineteen differentially methylated sites with RsaⅠ+HpaⅡ digestion and 14 differentially methylated sites with RsaⅠ+MspⅠ digestion between parental lines and the hybrid were found. All fragments detected in this study were grouped into four classes: (1) the same level of methylation in both parental lines and the hybrid; (2) the same level of methylation in one parent and the hybrid; (3) an increased level of methylation in the hybrid compared to the parents, and (4) a decreased level of methylation in the hybrid. Five sites had significant effects on 7 traits (P <0.05). Sequence analysis showed that three sequences had their match in GenBank with high identity (greater than 87%) and two sequences had no match in the database. G+C percent of three sequences was over 50, and observed/expected CpG of all sequences was above 0.6. Furthermore, one sequences contained G/C boxes. This study has demonstrated that sites in CpG islands within a gene promoter region were differentially methylated in the hybrid compared to parental lines; methylated sites exerted differentially on F1 performance, showing heterosis could benefit from expression or repression of some genes.

关 键 词：去甲基化 子代 AP-PCR 表达 基因 CPG岛甲基化 影响 生产性状 位点 扩增片段 

分 类 号：S513[农业科学—作物学] R735[医药卫生—肿瘤]