Non-random segregation of sister chromosomes in Escherichia coli

It has long been known that the 59 to 39 polarity of DNA synthesis results in both a leading and lagging strand at all replication forks(1). 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(2,3). Our work demonstrates a new level of organization relating to the replication and segregation of the E. coli chromosome.