Fig. 4. Scc1 cleavage as a landmark of anaphase onset. Cells expressing Scc1-HA were arrested in S-phase of the cell cycle by hydroxyurea then processed for tubulin immunostaining and western blot analysis (anti-HA) following release. The Scc1 band (asterisk) and cleavage-product band (arrowhead) are shown. Genotypes are indicated on the top of each panel. The time after release from S-phase arrest are indicated at the top of each lane. The percentage of cells with elongated anaphase spindles (>2.5 µm) are indicated at the bottom of each lane (% ana). Results are representative of three independent experiments. In each experiment, tubulin morphology of 150-200 anaphase cells was examined.