Figure 5.

Spindle elongation in top2-B44 cells depends on the APC. (A) Timing of Pds1-3xHA degradation in top2-B44 cells. Cells were released from G1 synchrony as described in Figure 1 and samples were taken for scoring budding and spindle morphologies, as well as for preparing whole-cell protein extracts for Western blots. Pds1 was detected using an anti-HA antibody, and as a loading control, Cdc28 was detected using the PSTAIRE antibody. Percent anaphase cells at each time point is indicated beneath the Western blots. (B) Cell cycle analysis of top2∷top2-B44 in combination with the apc2-4 mutation. Cells were synchronized in G1 at 26°C, then upon release from G1 the temperature was shifted up to 32°C, the nonpermissive temperature for the apc2-4 mutation. Budding and spindle morphologies were scored as described in Figure 1.