Fig. 8. A model for the maintenance of the two independent cell cycles of ovarian germline cysts. (A) High levels of Dap help maintain the oocyte in prophase of meiosis I (red) by inhibiting inappropriate DNA replication. In the nurse cells the cycling of Dap allows the periodic initiation of DNA replication during the endocycle (blue). (B) The balance of cyclinE-Cdk2 and its inhibitor Dap determine if a cyst cell enters the endocycle or arrests in meiosis (see text for details). Scissors indicate Dap proteolysis.