DNA Replication – Singled Out

DNA Replication – Singled Out

DNA replication is tightly regulated, since errors in replication would be passed on to daughter cells and essential information could be lost. In eukaryotic cells, an important regulatory step is the activation of replication origins, which leads to the formation of two replication forks that move away from the origin. Interestingly, the order by which replication origins activate is tightly regulated, as evident from the reproducible replication time of each chromosomal region. However, the information about this order was obtained from large populations of cells, therefore overlooking rare replication initiation events. 

Researchers from Conrad Nieduszynski’s group have developed a high-resolution method to study DNA replication at a single cell level. They treated budding yeast cells with low concentrations of a nucleotide analogue and used nanopore sequencing to detect the incorporation of the analogue, thus identifying nascent DNA. Based on the distribution of the analogue, they could identify replication origins and replication fork movement genome-wide. This is the first time that genome replication dynamics have been characterised by single-molecule sequencing.

Shaked Ashkanazi

Müller CA, Boemo MA, Spingardi P, Kessler BM, Kriaucionis S, Simpson JT, Nieduszynski CA (2019).

Nature Methods