A. Inhibition of Cdk1 at anaphase I. CDC20-mAR and CDC20-mAR cdc28-as1 cells were released from the metaphase I-arrest with CuSO4 at 7 h in SPM (t = 0) and treated with 1NM-PP1 at t = 40 min to inhibit Cdc28-as1 (arrows). Top, time-lapse series from the imaging of Mpc70-GFP, SPBs (Cnm67-RFP), and nuclei (TetR-RFP). Bottom, quantification of meiotic events. 