当一个细菌细胞复制其环状基因组时，一个染色体被连续合成（领头链），另一个染色体被不连续地合成（拖后链）。以前的研究表明，这种差别可能会决定一个染色体在细胞分裂时位置在哪里，但过去没有关于这一模型的直接证据。
White等人设计了一个能让他们跟踪每个链的体系，而且他们发现，一个染色体的两个版本被送到不同的细胞目的地。领头链被送到细胞极（cell pole）；拖后链被送到细胞中心。这些结果也与干细胞界正在争论的“不朽链”（immortal strand）假说有关。（生物谷Bioon.com）
生物谷推荐原始出处：
Nature 455, 1248-1250 (30 October 2008) | doi:10.1038/nature07282
Non-random segregation of sister chromosomes in Escherichia coli
Martin A. White1, John K. Eykelenboom1, Manuel A. Lopez-Vernaza1, Emily Wilson1 & David R. F. Leach1
Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, King's Buildings, Edinburgh EH9 3JR, UK
It has long been known that the 5' to 3' polarity of DNA synthesis results in both a leading and lagging strand at all replication forks. Until now, however, there has been no evidence that leading or lagging strands are spatially organized in any way within a cell. Here we show that chromosome segregation in Escherichia coli is not random but is driven in a manner that results in the leading and lagging strands being addressed to particular cellular destinations. These destinations are consistent with the known patterns of chromosome segregation. Our work demonstrates a new level of organization relating to the replication and segregation of the E. coli chromosome.
