Deposition of Acetylated Histones by RNAP II Promoter Clearance May Occur at Onset of Zygotic Gene Activation in Preimplantation Mouse Embryos
Deposition of Acetylated Histones by RNAP II Promoter Clearance May Occur at Onset of Zygotic Gene Activation in Preimplantation Mouse Embryos
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DOI：
10.1262/jrd.10-088m
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发表时间：
2010-12-01
影响因子：
1.8
通讯作者：
Matsumoto, Kazuya
中科院分区：
文献类型：
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作者：
Tokoro, Mikiko;Shin, Seung-Wook;Matsumoto, Kazuya
我们研究了磷酸化 RNA 聚合酶 II (RNAP II) 和动态表观遗传变化对次要合子基因激活 (ZGA) 起始的贡献。使用免疫荧光染色，我们观察到 RNAP IT 的核定位在授精后 6 小时 (hpi) 开始，而在羧基末端结构域 (CTD) 的丝氨酸残基 5 处磷酸化的 RNAP II 在 9 hpi 时定位，然后 RNAP II 在丝氨酸残基处磷酸化CTD 2 于 12 hpi 时定位于胚胎细胞核。在使用质粒报告基因 (p beta-actin/luciferase+/SV40) 在 6-9 hpi 期间注射到雄性原核的瞬时基因表达测定中，荧光素酶 + 基因分别在 13 hpi 和 15 hpi 时活跃转录和翻译，表明转录沉默状态在注射后至少持续 4 小时。我们发现鸡中的甲基化状态质粒报告基因的β-肌动蛋白启动子区域可能与小 ZGA 之前的转录沉默状态无关。暴露于曲古抑菌素 A 不会诱导注射到含有组蛋白脱乙酰酶活性的 1 细胞胚胎中的沉默报告基因过早表达，并且不会影响每个胚胎产生的荧光素酶量。乙酰化组蛋白 H3 赖氨酸 9/14 和乙酰化组蛋白 H4 赖氨酸 12 和 16 优先在注射的报告基因中富集。基因至少直到 13 hpi，这与转录活性状态一致 综上所述，这些结果表明，01 选择性乙酰化组蛋白沉积到 1 细胞胚胎的染色质上，与 RNAP II 的转录延伸一起发挥作用，并且这种连续的染色质重塑参与了与植入前小鼠胚胎中小 ZGA 的发生相关的分子机制。
We investigated the contribution of phosphorylated RNA polymerase II (RNAP II) and dynamic epigenetic changes to the onset of minor zygotic gene activation (ZGA) Using immunofluorescence staining, we observed that the nuclear Localization of RNAP IT was initiated by 6 hours post insemination (hpi), whereas RNAP II phosphorylated at serine residue 5 of the carboxyl-terminal domain (CTD) was localized by 9 hpi, and then RNAP II phosphorylated at serine residue 2 of the CTD was localized in the nucleus of embryos by 12 hpi In a transient gene expression assay using a plasmid reporter gene (p beta-actin/luciferase+/SV40) injected during 6-9 hpi into the male pronucleus, the luciferase+gene was actively transcribed and translated by 13 and 15 hpi, respectively, indicating that a transcriptionally silent state persisted for it least 4 hours after injection We found that the methylation status in the chicken beta-actin promoter region of the plasmid reporter gene may not be associated with the transcriptionally silent state before minor ZGA Exposure to trichostatin A did not induce premature expression of the silent reporter gene injected into 1-cell embryos containing histone deacetylase activity and did not affect the amount of luciferase produced per embryo Acetylated histone H3 lysine 9/14 and acetylated histone H4 lysine 12 and 16 were enriched preferentially in the injected reporter gene at least until 13 hpi, which coincided with the transcriptionally active state Taken together, these results suggest that deposition 01 selectively acetylated histones onto the chromatin of 1-cell embryos functions together with transcriptional elongation by RNAP II and that this sequential chromatin remodeling is involved in the molecular mechanism associated with the onset of minor ZGA in the preimplantation mouse embryo