Fig. 4.

Sgo1 is removed when the spindle assembly checkpoint is satisfied. Cells contained Sgo1-Δdb–GFP and Spc42–mCherry as in Fig. 3, as well as CDC20 under the control of the GAL promoter. In the presence of galactose (Gal, top panels), cells at all stages of the cell cycle were present. After shifting the cells into medium containing dextrose for 3 h, Cdc20 synthesis was shut off and cells arrested in mitosis (Dex, middle panels). Nocodazole (20 µg/ml) was then added to the arrested cells (Dex + Noc, bottom panels) to promote spindle disassembly. In two independent experiments with over 50 cells each, 6.7% (±1.4%; ±s.d.) of cells displayed Sgo1-Δdb–GFP foci in the presence of dextrose, and 93% (±2.2%; ±s.d.) of cells displayed foci following addition of nocodazole. BF, brightfield image. Scale bar: 5 µm.