以白洛克肉鸡和白来航蛋鸡及其杂交F1代基因组为实验材料, 应用甲基敏感扩增片段多态性方法(Methylation sensitive amplified polymorphism, MSAP) 检测了鸡肌肉、心脏、肝脏和肾脏4个不同组织基因组在CCGG位点的甲基化状态, 分析了不同组织的DNA甲基化水平及组织特异性甲基化模式。研究发现: 肌肉组织的甲基化水平约为29.7 %, 肝脏组织约为27.5%, 心脏组织约为27.5%, 肾脏组织约为26.1%; 在鸡3个不同群体及其中3个不同组织间, 基因组甲基化程度差异显著(P<0.05); 在检测的4个组织中, CCGG序列的全甲基化位点少于半甲基化位点, 与植物的相关研究不一致; 分离及鉴定了2个组织特异的甲基化片段。结果表明: 鸡不同组织基因组的甲基化状态是不同的, 同一组织的甲基化水平在不同的群体是不同的, 而不同组织甲基化水平的排序在不同的群体是不一致的。这些结果揭示遗传效应可能影响个体的组织甲基化水平。
关键词：
鸡; 基因组; 甲基化; MSAP; 群体
With methylation sensitive amplified polymorphism (MSAP), the DNA methylation levels and patterns of CCGG sites in genomes was analyzed among four different tissues and between parents and offsprings from three groups of adult chicken, White Leghorn, White Plymouth Rock, and their F1 hybrids. The results indicated that the degree of methylation was approximate 29.7% in muscle, 27.5% in liver, 27.5% in heart, and 26.1% in kidney. There was significantly different in the level of methylation in the 3 different groups and in 4 different tissues (P<0.05). The fully-methylated sites were less than the hemi-methylated sites among the 4 tissues, which was different from that of plants. The two tissue-specific MSAP fragments were isolated, sequenced, and characterized, both of which were located in the coding regions. These results clearly demonstrated that there was difference in the methylation level among various tissues and different groups, which suggested that the genetic factor may have effect on the individual methylation level.
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