Chromatin remodeling in somatic cells injected into mature pig oocytes
Chromatin remodeling in somatic cells injected into mature pig oocytes
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DOI：
10.1530/rep.1.00897
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发表时间：
2006-06-01
期刊：
影响因子：
3.8
通讯作者：
Miyano, Takashi
中科院分区：
文献类型：
--
作者：
Bui, Hong-Thuy;Van Thuan, Nguyen;Miyano, Takashi
我们研究了组蛋白H3修饰在注入成熟猪卵母细胞的体细胞细胞核的染色体凝聚和去凝聚过程中的作用。将猪颗粒细胞细胞核转移到体外成熟的完整猪卵母细胞中，用特异性抗体免疫染色检测组蛋白H3磷酸化、乙酰化和甲基化与染色体形态变化的关系。在11中期的猪卵母细胞浓缩染色体中，组蛋白H3在丝氨酸10位点（H3- s10）和丝氨酸28位点（H3- s28）磷酸化，在赖氨酸9位点（H3- k9）甲基化，但在赖氨酸9、14和18位点（H3- h9、H3- k14和H3- k18）未乙酰化。在核转移后的前2小时，在体细胞核中观察到一系列事件：核膜解体；染色体凝聚形成中期样结构；组蛋白H3磷酸化水平升高（H3- s10和H3- s28）。然后，将体细胞核注入猪卵母细胞电激活，观察卵母细胞和体细胞的染色体形态以及组蛋白修饰。一般来说，体细胞染色体的细胞周期阶段进展与卵母细胞相似，虽然纺锤体的形态与卵母细胞纺锤体的形态不同，但经过后期II和末期II样阶段，然后形成原核样结构。体细胞染色体也表现出组蛋白H3去磷酸化和再乙酰化的变化，与卵母细胞相似。相比之下，卵母细胞注射和电激活后，体细胞细胞核组蛋白H3甲基化（H3- k9）没有明显变化。这些结果表明，在卵母细胞细胞质的调控下，卵母细胞内发生了包括组蛋白H3磷酸化和体核乙酰化在内的核重构。
We examined the involvement of histone H3 modifications in the chromosome condensation and decondensation of somatic cell nuclei injected into mature pig oocytes. Nuclei of pig granulosa cells were transferred into in vitro matured intact pig oocytes, and histone H3 phosphorylation, acetylation, and methylation were examined by immunostaining with specific antibodies in relation to changes in chromosome morphology. In the condensed chromosomes of pig oocytes at metaphase 11, histone H3 was phosphorylated at serine 10 (H3-S10) and serine 28 (H3-S28), and methylated at lysine 9 (H3-K9), but was not acetylated at lysine 9, 14 and 18 (H3-H9, H3-K14 and H3-K18). During the first 2 h after nuclear transfer, a series of events were observed in the somatic nuclei: nuclear membrane disassembly; chromosome condensation to form a metaphase-like configuration; an increase in histone H3 phosphorylation levels (H3-S10 and H3-S28). Next, pig oocytes injected with nuclei of somatic cells were electroactivated and the chromosome morphology of oocytes and somatic cells was examined along with histone modifications. Generally, chromosomes of the somatic cells showed a similar progression of cell cycle stage to that of oocytes, through anaphase II- and telophase II-like stages then formed pronucleus-like structures, although the morphology of the spindles differed from that of oocyte spindles. The chromosomes of somatic cells also showed changes in histone H3 dephosphorylation and reacetylation, similar to oocytes. In contrast, histone H3 methylation (H3-K9) of somatic cell nuclei did not show any significant change after injection and electroactivation of the oocytes. These results suggest that nuclear remodeling including histone H3 phosphorylation and acetylation of injected somatic nuclei took place in the oocytes under regulation by the oocyte cytoplasm.