Figure 6.

The regulation of DNA replication licensing differs between the early embryo and larval somatic cells. (A) The control of replication licensing in larval somatic cells (see Figure 3 for components). (B) The regulation of replication licensing in the early embryo. Replication licensing occurs in mitosis. Replication licensing is prevented from reinitiating in S phase by the export of CDC-6 and the ORC complex (ORC1 and ORC2-5 exported separately). It is not known if CDC-6 remains associated with ORC components during S phase or if CDC-6 nuclear export is regulated by CDK phosphorylation (as in larval somatic cells). See text for details.