Figure 2.—

Chromosome segregation occurs normally in ssp2 and osw1. (A) Meiotic nuclear division was examined in wild-type, ssp2∷URA3, and osw1∷URA3 strains. Both binucleate and tetranucleate cells were scored as having undergone nuclear division. (B and C) Chromosome segregation was monitored in a strain that produces GFP–LacI fusion protein and is homozygous for a tandem array of LacO repeats inserted 22 kbp from CENIII. (B) An example of a cell that has undergone normal segregation is shown. Four DAPI-stained bodies indicate that chromosomes have undergone both meiotic divisions. One GFP dot per DAPI-stained body indicates that GFP-tagged chromosomes have segregated correctly. Bar, 2 μm. (C) Quantitation of GFP signals in wild-type, ssp2∷URA3, and osw1∷URA3 strains. Cells were harvested after 24 hr of sporulation, stained with DAPI, and examined by fluorescence microscopy. The percentages of cells with one, two, three, or four GFP dots are indicated. At least 100 cells were scored for each strain. The experiments shown in A and C were performed twice with qualitatively similar results.