FIG. 8.

A model for the temporal separation of template switching and translesion synthesis. Damaged bases encountered by the replicative polymerase during S-phase result in single-strand gaps behind the replication fork. There are two ways a cell can fill in these gaps: a recombination-based approach (such as template switching) using the newly formed sister strand as a template or error-prone translesion synthesis. Template switching can occur as soon as the replication fork has passed and the sister sequence is available. Recent evidence suggests that translesion synthesis does not occur until the end of S-phase and into Mitosis (Waters and Walker 2006). Therefore, a damaged base in late-replicating regions is more likely to be subjected to translesion synthesis than the same lesion in an early-replicating region. This figure is adapted from Waters and Walker (2006).