當(dāng)一個(gè)細(xì)菌細(xì)胞復(fù)制其環(huán)狀基因組時(shí),，一個(gè)染色體被連續(xù)合成（領(lǐng)頭鏈）,，另一個(gè)染色體被不連續(xù)地合成（拖后鏈）,。以前的研究表明,，這種差別可能會(huì)決定一個(gè)染色體在細(xì)胞分裂時(shí)位置在哪里,，但過去沒有關(guān)于這一模型的直接證據(jù),。
White等人設(shè)計(jì)了一個(gè)能讓他們跟蹤每個(gè)鏈的體系，而且他們發(fā)現(xiàn),，一個(gè)染色體的兩個(gè)版本被送到不同的細(xì)胞目的地,。領(lǐng)頭鏈被送到細(xì)胞極（cell pole）,；拖后鏈被送到細(xì)胞中心。這些結(jié)果也與干細(xì)胞界正在爭(zhēng)論的“不朽鏈”（immortal strand）假說(shuō)有關(guān),。（生物谷Bioon.com）
生物谷推薦原始出處：
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.
