在未受精的卵子中复制的能力是由Cdc6在介质成熟期间赋予的
Jean-Marc Lemaître1, Stéphane Bocquet, Marcel Méchali
1Institute of Human Genetics, CNRS, Genome Dynamics and Development, 141 Rue de la Cardonille, 34396 Montpellier Cedex 5, France.
Nature
|October 18, 2002
概括
在Xenopus蛋成熟时,Cdc6蛋白质合成对于DNA复制至关重要. 这一过程在成熟过程中触发,使卵子能够在受精前复制DNA,Cdc6是关键因素.
科学领域:
- 细胞生物学 细胞生物学
- 发展生物学 发展生物学
- 分子生物学分子生物学
背景情况:
- 介质成熟对于卵细胞发育至关重要,它将一个不成熟的卵细胞转化为可受精的卵子.
- 在Xenopus卵细胞成熟过程中,DNA复制能力获得了核包裹分解后的DNA复制能力.
- 一个特定的DNA合成诱导剂,在卵细胞中不存在,在成熟过程中被翻译.
研究的目的:
- 为了确定DNA合成诱导因子,负责Xenopus蛋中的复制能力.
- 阐明Cdc6在卵细胞成熟期间启动DNA复制中的作用.
主要方法:
- 鉴定Cdc6作为DNA合成诱导剂.
- 对母体cdc6mRNA和卵细胞中蛋白质储存的分析.
- 橄核酸反感注射和翻译抑制以阻止Cdc6合成.
- 使用重组Cdc6蛋白进行救援实验.
主要成果:
- 确定Cdc6对于招募小染色体维护 (MCM) 酶至关重要.
- 母亲的cdc6mRNA被储存,而Cdc6蛋白在成熟过程中被合成.
- 对于DNA复制能力来说,cdc6翻译是必要的,也是足够的.
- 细胞静止因子 (CSF) 途径防止S阶段进入直到受精.
结论:
- 介质成熟期间的Cdc6转化是赋予Xenopus蛋DNA复制能力的关键事件.
- Cdc6作为唯一必要和足够的复制因子,其合成是翻译调节的.
- 复制许可发生在化I结束时,但CSF积极抑制S阶段进入.
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The cell cycle is a series of events leading to DNA duplication followed by the division of cell content to form two daughter cells. The cell cycle progresses in four stages—the cell increases in size (gap 1 or G1-phase), duplicates its DNA (synthesis or S-phase), prepares to divide (gap 2 or G2-phase), and divides (mitosis or M-phase).
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In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of replication.
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