Fig 7. Model: The CycA—Myb—AurB network regulates the choice between cell cycle programs.

Depicted are two alternative cell cycle programs, the mitotic cycle (left), and endoreplication cycle (right, yellow). During mitotic cycles, CycA / CDK1 activates the Myb-MuvB (MMB) to induce transcription of multiple genes with mitotic functions (“mitotic” genes). Among these are the subunits of the chromosome passenger complex (CPC), which phosphorylates multiple targets to regulate chromosome condensation, kinetochore-microtubule (KT-MT) attachment, the spindle assembly checkpoint (SAC), and cytokinesis. Our findings suggest that CycA / CDK1, MMB, and the CPC are key nodes of this mitotic network whose repression promotes a transition to endoreplication in both iECs and devECs. See text for further details.