Figure 7.

clb5/clb5 clb6/clb6 mutants are unable to delay chromosome segregation in response to HU, but can delay in response to DNA damage. Wild-type (A) or clb5/clb5 clb6/clb6 (B) diploids were induced to sporulate in the absence of HU (█), or with 2.5 mm HU (▴), or 100 mm HU (•). Samples obtained at the indicated intervals were stained with DAPI to determine when chromosome segregation occurred (top, A,B), or were diluted and plated to determine viability (bottom, A,B). (C) Wild-type (□,█) or clb5/clb5 clb6/clb6 (○,•) diploids were induced to sporulate at 30°C and after 2 hr were subjected to either mock irradiation (open symbols) or γ irradiation with 200 gy (solid symbols). Following treatment, cultures were returned to 30°C and samples withdrawn at the indicated times and stained with DAPI to monitor chromosome segregation.