Activation of the old SPB is delayed in cut12.1 and cut11.1 mutants. (A–D) Wild-type (Wt) nmt81.atb2GFP (A; Video 1), cut7.24 nmt81.atb2GFP (B; Video 2), cut12.1 nmt81.atb2GFP (C; Video 3), or cut11.1 nmt81.atb2GFP (D; Video 4) cells were grown at 25°C and mounted for live imaging at 36°C. Images were captured every 4 min, and the time between the dissolution of the interphase microtubules and nucleation of mitotic microtubules was scored and plotted in E. (E) Numbers inside the circles correspond to the number of individual cells that spent this specific time interval (y axis) without microtubules (MT). For each strain, n = 15. Bar, 10 µm.