FIG. 6.

Genetic interactions involving Swi1 and Mus81. (A) Mus81 is vital for cell survival in CPT. Fivefold serial dilutions of cells were incubated for 2 to 3 days at 30°C on YES agar medium supplemented with 0 or 0.3 μM CPT. Growth of mus81 mutant cells was severely impaired by 0.3 μM CPT, whereas growth of wild-type and swi1 and checkpoint mutant strains was unaffected. The swi1 and checkpoint mutant strains were sensitive to higher concentrations of CPT (data not shown). (B) Mus81 and Rqh1 are vital in swi1 mutant background. Cells of indicated genotypes were grown in YES liquid medium and photographed. The swi1 mus81 and swi1 rqh1 double mutants showed a severe growth defect, with many elongated and vacuolated cells, whereas cds1 mus81 mutant cells and other single mutants grew relatively well.