Figure 5.—

Spindle integrity checkpoint activation in the clb3 clb4 double mutant. (A) Western blotting analysis showed that Pds1 degradation was delayed in the clb3 clb4 strain. Cells were synchronized at G₁ phase by α-factor, and the arrest was released by removing the α-factor from the media. Samples were taken every 20 min for 120 min, and Pds1-13XMYC and Clb2 were visualized. Anti-3-phosphoglycerate kinase (Pgk) antibodies were used for the loading control. The experiments were repeated twice, and the same results were obtained from both experiments. (B) FACS analysis was performed using the same samples obtained from the α-factor block and release. The samples were fixed with ethanol and stained with propidium iodide.