Kitamura Etsushi, Blow J Julian, Tanaka Tomoyuki U
School of Life Sciences, University of Dundee, Wellcome Trust Biocentre, Dow Street, Dundee, UK.
Cell. 2006 Jun 30;125(7):1297-308. doi: 10.1016/j.cell.2006.04.041.
Faithful DNA replication ensures genetic integrity in eukaryotic cells, but it is still obscure how replication is organized in space and time within the nucleus. Using timelapse microscopy, we have developed a new assay to analyze the dynamics of DNA replication both spatially and temporally in individual Saccharomyces cerevisiae cells. This allowed us to visualize replication factories, nuclear foci consisting of replication proteins where the bulk of DNA synthesis occurs. We show that the formation of replication factories is a consequence of DNA replication itself. Our analyses of replication at specific DNA sequences support a long-standing hypothesis that sister replication forks generated from the same origin stay associated with each other within a replication factory while the entire replicon is replicated. This assay system allows replication to be studied at extremely high temporal resolution in individual cells, thereby opening a window into how replication dynamics vary from cell to cell.
精确的DNA复制确保了真核细胞中的遗传完整性,但在细胞核内复制如何在空间和时间上进行组织仍不清楚。通过延时显微镜技术,我们开发了一种新方法来在空间和时间上分析单个酿酒酵母细胞中的DNA复制动态。这使我们能够可视化复制工厂,即由复制蛋白组成的核焦点,大量的DNA合成在此发生。我们表明,复制工厂的形成是DNA复制本身的结果。我们对特定DNA序列处复制的分析支持了一个长期存在的假设,即从同一复制起点产生的姐妹复制叉在整个复制子被复制时会在一个复制工厂内彼此保持关联。该检测系统允许在单个细胞中以极高的时间分辨率研究复制,从而为了解复制动态如何在细胞间变化打开了一扇窗口。