RT Journal Article SR Electronic T1 Single-molecule mapping of replisome progression JF bioRxiv FD Cold Spring Harbor Laboratory SP 2022.01.10.475700 DO 10.1101/2022.01.10.475700 A1 Claussin, Clémence A1 Vazquez, Jacob A1 Whitehouse, Iestyn YR 2022 UL http://biorxiv.org/content/early/2022/01/11/2022.01.10.475700.abstract AB Fundamental aspects of DNA replication, such as the anatomy of replication stall sites, how replisomes are influenced by gene transcription and whether the progression of sister replisomes is coordinated are poorly understood. Available techniques do not allow the precise mapping of the positions of individual replisomes on chromatin. We have developed a new method called Replicon-seq that entails the excision of full-length replicons by controlled nuclease cleavage at replication forks. Replicons are sequenced using Nanopore, which provides a single molecule readout of long DNA molecules. Using Replicon-seq, we have investigated replisome movement along chromatin. We found that sister replisomes progress with remarkable consistency from the origin of replication but function autonomously. Replication forks that encounter obstacles pause for a short duration but rapidly resume synthesis. The helicase Rrm3 plays a critical role both in mitigating the effect of protein barriers and facilitating efficient termination. Replicon-seq provides an unprecedented means of defining replisome movement across the genome.Competing Interest StatementThe authors have declared no competing interest.