Kim Seok-Ho, Kang Yong-Kook, Koo Deog-Bon, Kang Man-Jong, Moon Seung-Ju, Lee Kyung-Kwang, Han Yong-Mahn
Laboratory of Development and Differentiation, Korea Research Institute of Bioscience and Biotechnology (KRIBB), P.O. Box 115, Yuseong, Daejeon 305-600, Republic of Korea.
Biochem Biophys Res Commun. 2004 Nov 5;324(1):58-63. doi: 10.1016/j.bbrc.2004.09.023.
Genome-wide changes of DNA methylation by active and passive demethylation processes are typical features during preimplantation development. Here we provide an insight that epigenetic reprogramming of DNA methylation is regulated in a region-specific manner, not a genome-wide fashion. To address this hypothesis, methylation states of three repetitive genomic regions were monitored at various developmental stages in the mouse embryos. Active demethylation was not observed in the IAP sequences whereas methylation reprogramming of the satellite sequences was regulated only by the active mechanism. Etn elements were actively demethylated after fertilization, passively demethylated by the 8-cell stage, and de novo methylated at the morular and blastocyst stages, showing dynamic epigenetic changes. Thus, our findings suggest that the specific genomic regions or sequences may spatially/temporally have their unique characteristics in the reprogramming of the DNA methylation during preimplantation development.
通过主动和被动去甲基化过程实现的全基因组DNA甲基化变化是着床前发育过程中的典型特征。在此，我们提供了一个见解，即DNA甲基化的表观遗传重编程是以区域特异性方式调控的，而非全基因组范围的方式。为验证这一假设，我们在小鼠胚胎的不同发育阶段监测了三个重复基因组区域的甲基化状态。在IAP序列中未观察到主动去甲基化，而卫星序列的甲基化重编程仅由主动机制调控。Etn元件在受精后被主动去甲基化，在8细胞阶段被被动去甲基化，并在桑葚胚和囊胚阶段发生从头甲基化，呈现出动态的表观遗传变化。因此，我们的研究结果表明，在着床前发育过程中，特定的基因组区域或序列在DNA甲基化重编程方面可能在空间/时间上具有其独特特征。
