The Pathway Ontology (PW), is currently being developed at the Rat Genome Database. For more information about this vocabulary, please see Petri et al. The rat genome database pathway portal. Database (Oxford). 2011 Apr 8;2011:bar010. Print 2011 or contact us (http://rgd.mcw.edu/contact/index.shtml).
Those pathways that assure the genome is replicated only once per cell cycle. The checkpoints control for damaged and un-replicated DNA. Un-replicated DNA signals to block the cell cycle from proceeding. The mechanism by which the cell detects un-replicated DNA is not known.