Roles of the first and second round of DNA replication in the regulation of zygotic gene activation in mice.
Roles of the first and second round of DNA replication in the regulation of zygotic gene activation in mice.
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DOI：
10.1262/jrd.20053
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发表时间：
2008-06
期刊：
影响因子：
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通讯作者：
Hiroki Sonehara;M. Nagata;F. Aoki
中科院分区：
文献类型：
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作者：
Hiroki Sonehara;M. Nagata;F. Aoki
在小鼠胚胎中，合子基因的表达开始于1细胞期的S/G2期，并在2细胞期大大增加。虽然合子基因激活（ZGA）的时间，从而建立，ZGA的调控机制知之甚少。以前使用报告基因的研究表明，在2-细胞阶段建立了转录抑制状态，并且第一轮和第二轮DNA复制参与了这一过程。为了进一步阐明ZGA中两轮DNA复制各自的作用，我们分析了4个ZGA基因（hsp70.1，eif-1a，muerv和zscan 4d）在胚胎中的表达，这些胚胎的DNA复制被DNA聚合酶抑制剂aphidicolin抑制。抑制第一轮增加了hsp70.1、eif-1a和zscan 4d的表达水平，但降低了muerv的表达水平，而抑制第二轮增加了所有四个基因的表达水平。这些结果表明，转录抑制状态似乎是在第二轮DNA复制后建立的。
In the mouse embryo, expression of zygotic genes starts in the S/G2 phase of the 1-cell stage and greatly increases during the 2-cell stage. Although the timing of zygotic gene activation (ZGA) is thus established, the mechanism regulating ZGA is poorly understood. Previous studies using reporter genes have suggested that a transcriptionally repressive state is established during the 2-cell stage and that the first and second rounds of DNA replication are involved in this process. To further elucidate the respective roles of the two rounds of DNA replication in ZGA, we analyzed the expression of four ZGA genes (hsp70.1, eif-1a, muerv and zscan4d) in embryos whose DNA replication was inhibited by treatment with aphidicolin, an inhibitor of DNA polymerase. Inhibiting the first round increased the expression levels of hsp70.1, eif-1a and zscan4d but decreased that of muerv, while inhibiting the second round increased the expression levels of all four genes. These results suggest that the transcriptionally repressive state seems to be established after the second round of DNA replication.