EVIDENCE FOR CYTOSINE METHYLATION OF NONSYMMETRICAL SEQUENCES IN TRANSGENIC PETUNIA-HYBRIDA
EVIDENCE FOR CYTOSINE METHYLATION OF NONSYMMETRICAL SEQUENCES IN TRANSGENIC PETUNIA-HYBRIDA
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DOI：
10.1002/j.1460-2075.1994.tb06483.x
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发表时间：
1994-05-01
期刊：
影响因子：
11.4
通讯作者：
TENLOHUIS, M
中科院分区：
文献类型：
--
作者：
MEYER, P;NIEDENHOF, I;TENLOHUIS, M
植物中相当大比例的胞嘧啶残基在碳5处甲基化。根据公认的规律，胞嘧啶甲基化仅限于对称序列，如CpG和CpNpG，它们为维持甲基化酶忠实传递对称甲基化模式提供信号。利用基因组测序技术，我们分析了矮牵牛转基因高甲基化和低甲基化状态下的胞嘧啶甲基化模式。对部分转基因启动子的检测显示，在这两种状态下，都可以检测到位于非对称序列内的m(5)C残基。两种状态下的非对称C残基甲基化频率分别为5.9%和31.9%。甲基化似乎分布不均，但一些DNA区域的甲基化程度比其他区域高。我们的研究结果表明，至少在一个转基因中，一个不依赖于靶序列对称性的异质甲基化模式可以被建立和保守。
A considerable proportion of cytosine residues in plants are methylated at carbon 5. According to a well-accepted rule, cytosine methylation is confined to symmetrical sequences such as CpG and CpNpG, which provide the signal for faithful transmission of symmetrical methylation patterns by maintenance methylase. Using a genomic sequencing technique, we have analysed cytosine methylation patterns within a hypermethylated and a hypomethylated state of a transgene in Petunia hybrida. Examination of a part of the transgene promoter revealed that in both states m(5)C residues located within non-symmetrical sequences could be detected. Non-symmetrical C residues in the two states were methylated at frequencies of 5.9 and 31.9%, respectively. Methylation appeared to be distributed heterogeneously, but some DNA regions were more intensively methylated than others. Our results show that at least in a transgene, a heterogeneous methylation pattern, which does not depend on symmetry of target sequences, can be established and conserved.