Fig. 7. The SIN is required for spore formation. (A) Microscopy of living pat1-114/pat1-114 and pat1-114/pat1-114 cdc11-136/cdc11-136 cells expressing chromosomally tagged Cdc7p-GFP (left) or Sid1p-GFP (right). Cells were induced to undergo meiosis by incubation for 6 hours at 34°C. (B) Analysis of the kinetics of meiosis in pat1-114/pat1-114, pat1-114/pat1-114 spg1-B8/spg1-B8 and pat1-114/pat1-114 sid1-C14/sid1-C14 cells. Starved cells were induced to sporulate at 34°C, and a portion of the culture was fixed at the indicated time and stained with DAPI. Meiotic cells were classified by the number of nuclei per cell. , mononucleate cells; , binucleate cells; , tetranucleate cells. (C) cdc2-N22 cells of opposite mating types expressing Cdc7p-GFP were mated on EMM-NH₄Cl plates at 25°C for 24 hours. Cells were then resuspended in EMM-NH₄Cl and GFP fluorescence was examined. Bar, 10 µm.