CycE and Cdk2 are required for GSC maintenance; this role is at least in part genetically separable from cell cycle regulation. (A-D) Mosaic germaria showing control (A), null CycEAR95 (B), hypomorphic CycEWX (C) and null Cdk23 (D) GFP-negative clones. GFP (green), wild-type control cells; 1B1 (red), fusomes; LamC (red), cap cell nuclear envelopes; DAPI (blue), nuclei. GSCs are outlined. Arrows indicate GSC loss events. Scale bar: 5 μm. (E) Percentage of germline-mosaic germaria with a GSC loss event 8 or 12 days after clone induction. Numbers in the bars represent the number of germline-mosaic germaria analyzed. *P<0.0001.