Figure 1From: Can eukaryotic cells monitor the presence of unreplicated DNA?Overview of replication fork conditions that could trigger a checkpoint response. Inhibition of DNA replication by nucleotide depletion or DNA damage, and unfired licensed origins trigger S phase checkpoint activation, whereas unreplicated centromeres could trigger the activation of the spindle checkpoint due to lack of tension at kinetochores. However unreplicated segments of DNA in non-centromeric sites and the presence of forks at natural protein-DNA complexes, like the RFB sites on rDNA genes, do not trigger a checkpoint response.Back to article page