Regulation of replicon size in Xenopus egg extracts
Regulation of replicon size in Xenopus egg extracts
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DOI：
10.1126/science.275.5302.993
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发表时间：
1997-02-14
期刊：
影响因子：
56.9
通讯作者：
Newport, JW
中科院分区：
文献类型：
--
作者：
Waiter, J;Newport, JW
一旦在早期非洲爪蟾胚胎中产生了特定数量的细胞，在细胞周期的S期期间复制子的大小就会增加。在这里，据报道，类似的增加复制子的大小发生时，在复制能力的非洲爪蟾卵提取物中的细胞核的浓度超过临界阈值。在该系统中，起始识别复合物（ORC）没有变得化学计量限制起始，并且类似量的该复合物与染色质结合，而不管复制子大小。这些数据表明，在早期发育中，一个未知的因素控制着有多少预先形成的ORC-DNA复合物启动DNA复制。
Once a specific number of cells have been produced in the early Xenopus laevis embryo, replicon size during the S phase of the cell cycle increases. Here, it is reported that similar increase in replicon size occurred when the concentration of nuclei in replication-competent Xenopus egg extracts exceeded a critical threshold. In this system, the origin recognition complex (ORC) did not become stoichiometrically limiting for initiation, and similar amounts of this complex bound to chromatin regardless of replicon size. These data suggest that in early development, an unidentified factor controls how many preformed ORC-DNA complexes initiate DNA replication.