DNA combing reveals intrinsic temporal disorder in the replication of yeast chromosome VI
DNA combing reveals intrinsic temporal disorder in the replication of yeast chromosome VI
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DOI：
10.1016/j.jmb.2007.10.046
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发表时间：
2008-01-04
影响因子：
5.6
通讯作者：
Shao, Zhifeng
中科院分区：
文献类型：
--
作者：
Czajkowsky, Daniel M.;Liu, Jie;Shao, Zhifeng
一般认为，大多数真核生物中的DNA复制是按照一个精确的程序进行的，其中每个染色体区域复制都有一个确定的时间顺序。然而，这个程序在单个染色体水平上的规律性，在相对时间和DNA结构域的大小方面，还没有得到解决。在这里，染色体VI同步芽殖酵母的复制进行了研究，在一个类似的分辨率为1 kb的DNA梳和荧光显微镜。与严格的时间程序所预期的细胞相反，没有两个分子表现出相同的复制模式。此外，直接评估远距离染色体片段复制的协调程度表明，绝大多数这些片段是独立复制的。重要的是，平均所有的纤维检查的模式概括了总体平均模式从染色体VI的复制的人口研究。因此，而不是一个绝对定义的时间顺序的复制，复制时间似乎基本上是概率在个别细胞内，表现出扩展域内的时间趋势。(c)2007爱思唯尔有限公司版权所有。
It is generally believed that DNA replication in most eukaryotes proceeds according to a precise program in which there is a defined temporal order by which each chromosomal region is duplicated. However, the regularity of this program at the level of individual chromosomes, in terms of both the relative timing and the size of the DNA domain, has not been addressed. Here, the replication of chromosome VI from synchronized budding yeast was studied at a resolution of similar to 1 kb with DNA combing and fluorescence microscopy. Contrary to what would be expected from cells following a rigorous temporal program, no two molecules exhibited the same replication pattern. Moreover, a direct evaluation of the extent to which the replication of distant chromosomal segments was coordinated indicates that the overwhelming majority of these segments were replicated independently. Importantly, averaging the patterns of all the fibers examined recapitulates the ensemble-averaged patterns obtained from population studies of the replication of chromosome VI. Thus, rather than an absolutely defined temporal order of replication, replication timing appears to be essentially probabilistic within individual cells, exhibiting only temporal tendencies within extended domains. (c) 2007 Elsevier Ltd. All rights reserved.