Bolen P L, Grant D M, Swinton D, Boynton J E, Gillham N W
Cell. 1982 Feb;28(2):335-43. doi: 10.1016/0092-8674(82)90351-8.
Based on analysis by high pressure liquid chromatography, greater than 35% of the cytosine residues in chloroplast DNA of vegetative cells were found to be methylated constitutively in the nuclear gene mutation (me-1) of Chlamydomonas reinhardtii, which has an otherwise wild-type phenotype. Digestion of chloroplast DNA from vegetative cells and gametes of this mutant with restriction endonucleases Hpa II and Msp I reveals that in the 5'CCGG3' sequence, CpG is methylated extensively, whereas CpC is only methylated occasionally. Hae III (5'GGCC3') digestion of the mutant chloroplast DNA also shows extensive methylation of the GpC sequence. In contrast to the results of Sager and colleagues, which show a correlation between methylation of chloroplast DNA and transmission of chloroplast genes in crosses, our results with crosses of the me-1 mutant suggest that extensive chloroplast DNa methylation may be insufficient to account for the pattern of inheritance of chloroplast genes in Chlamydomonas.
基于高压液相色谱分析，在莱茵衣藻核基因突变（me-1）的营养细胞叶绿体DNA中，超过35%的胞嘧啶残基被发现组成型甲基化，该突变体具有野生型表型。用限制性内切酶Hpa II和Msp I消化该突变体营养细胞和配子的叶绿体DNA发现，在5'CCGG3'序列中，CpG被广泛甲基化，而CpC只是偶尔甲基化。用Hae III（5'GGCC3'）消化该突变体的叶绿体DNA也显示GpC序列存在广泛甲基化。与Sager及其同事的结果相反，他们的结果显示叶绿体DNA甲基化与杂交中叶绿体基因的传递之间存在相关性，我们对me-1突变体杂交的结果表明，叶绿体DNA的广泛甲基化可能不足以解释衣藻中叶绿体基因的遗传模式。
