Progressive segregation of the Escherichia coli chromosome
Progressive segregation of the Escherichia coli chromosome
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DOI：
10.1111/j.1365-2958.2006.05245.x
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发表时间：
2006-07-01
影响因子：
3.6
通讯作者：
Austin, Stuart
中科院分区：
文献类型：
--
作者：
Nielsen, Henrik J.;Li, Yongfang;Austin, Stuart
我们使用高效的标记系统和自动化测量，在缓慢生长的活细胞中跟踪了大肠杆菌染色体周围14个不同基因座的命运。基因座在复制时是分离的，但有明显的延迟。大多数标记从起点到终点都以平稳的时间顺序分离。因此，总体模式是一种在复制过程中连续分离的模式，与最近发表的调用广泛的姐妹染色体凝聚力随后同时分离大部分染色体的模型不一致。末端和紧靠原点顺时针方向的区域是整体模式的例外，在分离之前会经历更广泛的延迟。起始区和附近的基因座被复制并从细胞中心分离，随后标记从它们在类核中的不同位置被复制和分离，末端区域从细胞中心被复制和分离。分离似乎将每个基因座的一个拷贝留在原地，并迅速将另一个拷贝转移到细胞中心的另一边。
We have followed the fate of 14 different loci around the Escherichia coli chromosome in living cells at slow growth rate using a highly efficient labelling system and automated measurements. Loci are segregated as they are replicated, but with a marked delay. Most markers segregate in a smooth temporal progression from origin to terminus. Thus, the overall pattern is one of continuous segregation during replication and is not consistent with recently published models invoking extensive sister chromosome cohesion followed by simultaneous segregation of the bulk of the chromosome. The terminus, and a region immediately clockwise from the origin, are exceptions to the overall pattern and are subjected to a more extensive delay prior to segregation. The origin region and nearby loci are replicated and segregated from the cell centre, later markers from the various positions where they lie in the nucleoid, and the terminus region from the cell centre. Segregation appears to leave one copy of each locus in place, and rapidly transport the other to the other side of the cell centre.