Involvement of chromatin structure in the regulation of mouse zygotic gene activation.
Involvement of chromatin structure in the regulation of mouse zygotic gene activation.
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DOI：
10.1046/j.1344-3941.2002.00017.x
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发表时间：
2002-01-01
影响因子：
2
通讯作者：
Aoki, F.
中科院分区：
文献类型：
--
作者：
Cho, T.;Sakai, S.;Aoki, F.
我们通过体外转录实验和原位DNase I敏感性实验研究了染色质结构的整体变化在小鼠胚胎受精卵基因激活调控机制中的作用。从1-细胞晚期到2-细胞晚期，DNase I敏感性和转录活性的变化相似，但不在1-细胞早期。与早期1-细胞相比，DNase I在1-细胞晚期的敏感性降低。在2-细胞早期增加，在2-细胞晚期减少。类似地，转录活性在2-细胞早期比1-细胞晚期增加，然后在2-细胞晚期降低。在第一轮DNA复制被抑制的情况下，用aphidiclin处理的胚胎对DNase I的敏感性没有降低。当第二次DNA复制被抑制时，在胚胎中也观察到了类似的结果。这些结果表明，染色质结构是调控1-细胞晚期基因表达的重要因素之一，DNA复制是染色质结构中负责建立抑制状态的事件。蛋白质合成的抑制并不影响1-细胞胚胎对DNase I的敏感性，但已知蛋白质合成是基因激活所必需的。这一结果表明，负责启动基因激活的是受精后合成的蛋白质，而不是染色质结构。
We investigated the contribution of the global changes in chromatin structure to the mechanism regulating zygotic gene activation in mouse embryos by in vitro transcription assay and in situ DNase I sensitivity assay. Changes in the DNase I sensitivity and transcriptional activity were similar from the late 1-cell to the late 2-cell stage, but were not in the early 1-cell stage. DNase I sensitivity decreased at the late 1-cell stage when compared with the sensitivity at the early 1-cell stage. It increased at the early 2-cell stage and then decreased at the late 2-cell stage. Similarly, transcriptional activity increased at the early 2-cell stage when compared with the activity at the late 1-cell stage, and then decreased at the late 2-cell stage. DNase I sensitivity was not decreased in embryos that were treated with aphidicolin, where the first round of DNA replication was inhibited. A similar result was observed in embryos when the second DNA replication was inhibited. These results suggest that the chromatin structure is one of the important factors regulating gene expression from the late 1-cell stage and that DNA replication is an event responsible for the establishment of the repressive state in the chromatin structure. The inhibition of protein synthesis did not affect the DNase I sensitivity in the 1-cell embryos, while it is known that protein synthesis is indispensable for gene activation. This result suggests that the protein synthesized after fertilization, but not the chromatin structure, is responsible for the initiation of gene activation.