Recombination occurs within minutes of replication blockage by RTS1 producing restarted forks that are prone to collapse
The completion of genome duplication during the cell cycle is threatened by the presence of replication fork barriers (RFBs). Following collision with a RFB replication proteins can dissociate from the stalled fork (fork collapse) rendering it incapable of further DNA synthesis unless recombination intervenes to restart replication. We use time-lapse microscopy and genetic assays to show that recombination is initiated within ~10 minutes of replication fork blockage at a site-specific barrier in fission yeast, leading to a restarted fork within ~60 minutes, which is only prevented/curtailed by the arrival of the opposing replication fork. The restarted fork is susceptible to further collapse causing hyper-recombination downstream of the barrier. Surprisingly, in our system fork restart is unnecessary for maintaining cell viability. Seemingly the risk of failing to complete replication prior to mitosis is sufficient to warrant the induction of recombination even though it can cause deleterious genetic change.
Article and author information
- Stephen C Kowalczykowski, University of California, Davis, United States
- Received: August 28, 2014
- Accepted: March 24, 2015
- Accepted Manuscript published: March 25, 2015 (version 1)
- Version of Record published: April 23, 2015 (version 2)
© 2015, Nguyen et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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