Cdc13, a mitotic B-cyclin, is not decreased in the G1-arrested ste9 mutant. Extracts were prepared from cdc10 (lanes 1–4) or ste9 cdc10 (lanes 5–8) strains. Cells were cultured at 36°C for 0 h (lanes 1 and 5), 2 h (lanes 2 and 6), 3 h (lanes 3 and 7), and 4 h (lanes 4 and 8). Western blotting was carried out using anti-Cdc13 antibody (upper panel) or anti-PSTAIRE antibody for the loading control (lower panel). The location of Cdc13 is indicated by the arrow. The lower bands (indicated by asterisk) are unknown protein cross-reacted with the anti-Cdc13 antibody.