Holliday R
Genetics Division, National Institute for Medical Research, Mill Hill, London, United Kingdom.
Science. 1987 Oct 9;238(4824):163-70. doi: 10.1126/science.3310230.
Evidence from many sources shows that the control of gene expression in higher organisms is related to the methylation of cytosine in DNA, and that the pattern of methylation is inherited. Loss of methylation, which can result from DNA damage, will lead to heritable abnormalities in gene expression, and these may be important in oncogenesis and aging. Transformed permanent lines often lose gene activity through de novo methylation. It is proposed that epigenetic defects in germline cells due to loss of methylation can be repaired by recombination at meiosis but that some are transmitted to offspring.
来自多个来源的证据表明，高等生物中基因表达的调控与DNA中胞嘧啶的甲基化有关，并且甲基化模式是可遗传的。DNA损伤可能导致甲基化缺失，这将导致基因表达的可遗传异常，而这些异常可能在肿瘤发生和衰老过程中起重要作用。转化的永久细胞系常常通过从头甲基化失去基因活性。有人提出，由于甲基化缺失导致的生殖细胞中的表观遗传缺陷可在减数分裂时通过重组修复，但有些缺陷会传递给后代。
