sentences:  The ORC, Cdc6, and Cdt1 together are required for the stable association of the Mcm2-7 complex with replicative origins during G1 phase of the cell cycle.Eukaryotic origins of replication control the formation of a number of protein complexes that lead to the assembly of two bidirectional DNA replication forks.These events are initiated by the formation of the pre-replication complex (pre-RC) at the origins of replication.