Figure 2.

Sister chromatid cohesion is normal in brn1 mutant cells. The centromeric region of chromosome IV in these strains is tagged with an array of Lac operator repeats and visualized by expressing LacI::GFP fusion protein. GFP fluorescence (bright dots) is shown overlaid onto DIC images of cells. Wild-type (A) and brn1-60 mutant (B) cells were incubated at 37°C for 3 h in the presence of nocodazole. The two sister centromeres appear as a single dot in >90% of wild-type and mutant cells under these conditions (200 cells of each type scored).