Figure 5.

Ctf7p is required for sister chromatid cohesion. (A) Micrographs of wild-type and ctf7 mutant cells grown for 3 hr at 37°C in medium containing nocodazole and processed for FISH. A single FISH signal represents paired sister chromatids, two FISH signals represents disjoined sister chromatids. (red) Propidium iodide staining DNA mass; (green) hybridization to CEN16 probe. (B) Quantification of single (nondisjoined chromosomes) vs. double FISH signals (disjoined chromosomes) within propidium iodide staining DNA masses. Synchronized G₁ wild-type and ctf7 cells contained an equal percentage of single FISH signals (data not shown), indicating that the increase in two FISH signals observed for ctf7 mutant cells was not due to pre-existing aneuploid.