Asai T, Bates D B, Boye E, Kogoma T
Department of Cell Biology, University of New Mexico Health Sciences Center, Albuquerque 87131, USA.
Mol Microbiol. 1998 Aug;29(3):671-5. doi: 10.1046/j.1365-2958.1998.00901.x.
Initiation of chromosome replication is a key event in the life cycle of any organism. Little is known, however, about the regulatory mechanisms of this vital process. Conventionally, the initiation mechanism of chromosome replication in microorganisms has been studied using plasmids in which an origin of chromosome replication has been cloned, rather than using the chromosome itself. The reason for this is that even bacterial chromosomes are so large that biochemical and genetic manipulations become difficult and cumbersome. Recently, the combination of flow cytometry and genetic methods, in which modifications of the replication origin are systematically introduced onto the chromosome, has made possible detailed studies of the molecular events involved in the control of replication initiation in Escherichia coli. The results indicate that requirements for initiation at the chromosomal origin, oriC, are drastically different from those for initiation at cloned oriC.
染色体复制的起始是任何生物体生命周期中的关键事件。然而，对于这一重要过程的调控机制却知之甚少。传统上，微生物中染色体复制的起始机制是通过克隆了染色体复制起点的质粒来研究的，而不是使用染色体本身。这样做的原因是，即使是细菌染色体也非常大，以至于生化和基因操作变得困难且繁琐。最近，流式细胞术和基因方法相结合，其中将复制起点的修饰系统地引入到染色体上，使得对大肠杆菌中复制起始控制所涉及的分子事件进行详细研究成为可能。结果表明，染色体起点oriC处起始的要求与克隆的oriC处起始的要求截然不同。
