APC/C-Cdh1 is critical for sister-chromatid separation during mitotic slippage. (A, B) Cells of strains SCU399 (bub2Δ CEN-GFP), SCU410 (bub2Δ CEN-GFP MET3-CDC20) and SCU1336 (bub2Δ CEN-GFP cdh1Δ) were released from α-factor into the nocodazole-containing SGalR medium (time 0), as described in Figure 1. Representative cells at the 6 h time point are shown. Expression of MET3 promoter-driven CDC20 in strain SCU410 was shut off by the addition of methionine. The data for bub2Δ cells are taken from Figure 1, for comparison.