Research

1) Chromosome duplication in space and time

Chromosome duplication is a highly organized process both in space and time (Ref 1). DNA replication is initiated from defined origins and proceeds with replication forks travelling bi-directionally from origins. Using time-lapse microscopy, we have developed a novel assay to analyse dynamics of DNA replication in live cells (Ref 2) in collaboration with J. Julian Blow (Dundee). We found that sister replication forks, generated from the same origin, are associated with each other during DNA replication (Figure). This assay enables us to study in further detail how chromosome duplication is regulated spatially and temporally and how the dynamics vary from cell to cell.

Figure. Sister replication forks stay associated during replication. TetOs and lacOs were situated within the same replicon but at opposite sides of a replication origin. They are brought together, increase in intensity and subsequently come apart.

< References >

1. Natsume T & Tanaka TU. Spatial regulation and organization of DNA replication within the nucleus. Chrom Res, 18, 7-17. (2010)

2. Kitamura E, Blow JJ & Tanaka TU. Live-cell imaging reveals replication of individual replicons in eukaryotic replication factories. Cell 125, 1297-308. (2006)