Laboratoire de Physiologie Végétale, E.R.A. No. 226 du CNRS, Universite de Perpignan, 66025 Perpignan-Cedex, France.
Plant Physiol. 1984 Nov;76(3):627-32. doi: 10.1104/pp.76.3.627.
The methylation pattern of radish Raphanus sativus nuclear rDNA has been investigated using the Hpa II, Msp I, and Hha I restriction enzymes. The presence of numerous target sites for these enzymes has been shown using cloned rDNA fragments. A large fraction of the numerous rDNA units are heavily methylated, being completely resistant to Hpa II and Hpa I. However, specific sites are constantly available in another fraction of the units and are therefore unmethylated. The use of different probes allowed us to demonstrate that hypomethylated sites are present in different regions. Major hypomethylated Hha I sites have been mapped in the 5' portion of 25S rRNA coding sequence. Among the hypomethylated fraction, different methylation patterns coexist. It has been possible to demonstrate that methylation patterns are specific for particular units. The Hha I pattern of rDNA in tissues of different developmental stages was analyzed. Evidence for possible tissue specific differences in the methylation pattern is reported.
利用 Hpa II、Msp I 和 Hha I 三种限制酶，研究了萝卜 Raphanus sativus 核 rDNA 的甲基化模式。通过克隆 rDNA 片段，发现这些酶有许多靶位。大量 rDNA 单位高度甲基化，完全抵抗 Hpa II 和 Hpa I。然而，在另一部分单位中，特定的位点始终存在，因此是非甲基化的。使用不同的探针，我们证明了低甲基化的位点存在于不同的区域。在 25S rRNA 编码序列的 5' 部分，已经定位了主要的低甲基化 Hha I 位点。在低甲基化部分中，存在不同的甲基化模式。已经证明，甲基化模式是特定于特定单位的。分析了不同发育阶段组织中 rDNA 的 Hha I 模式。报道了甲基化模式可能存在组织特异性差异的证据。
Zotero 插件
