Barry C, Faugeron G, Rossignol J L
Institut de Génétique et Microbiologie, Centre National de la Recherche Scientifique Unité de Recherche Associée 1354, Université Paris-Sud, Orsay, France.
Proc Natl Acad Sci U S A. 1993 May 15;90(10):4557-61. doi: 10.1073/pnas.90.10.4557.
The effect of duplications of gene fragments on the triggering of DNA methylation induced premeiotically (MIP) was studied in the sexual progeny of strains harboring, in addition to the resident met2 gene, a fragment of this gene inserted at an ectopic position. Cytosine methylation of the resident gene was checked for each of the eight duplications tested. Methylation was always found and it was coextensive with the length of the duplications. Silencing of the resident gene was triggered by duplications of segments corresponding to the region 5' to the open reading frame, to only the open reading frame, or to segments beginning 0.87-1.2 kb downstream from the transcription start. Silencing was accompanied by either the absence of transcripts or the presence of truncated transcripts, which suggests that methylation acts on transcript elongation.
研究了基因片段重复对减数分裂前诱导的DNA甲基化（MIP）触发的影响，这些研究是在除了驻留的met2基因外，还在异位位置插入了该基因片段的菌株的有性子代中进行的。对所测试的八个重复中的每一个都检查了驻留基因的胞嘧啶甲基化情况。总是能发现甲基化，并且其与重复的长度共扩展。驻留基因的沉默是由对应于开放阅读框5'区域的片段、仅开放阅读框或转录起始下游0.87 - 1.2 kb处开始的片段的重复触发的。沉默伴随着转录本的缺失或截短转录本的存在，这表明甲基化作用于转录本的延伸。
