FIG. 2.

Override of the morphogenesis checkpoint by overexpression of HSL1 or HSL7. (A) Strains DLY657 (cdc24-1 SWE1) (○), DLY690 (cdc24-1 swe1Δ) (●), and JMY1284 (cdc24-1 SWE1 GAL:HSL7:LEU2) (□) were grown overnight at 24°C (permissive temperature) in YEPG to induce the GAL promoter, synchronized in G₁ phase with α-factor, and released into fresh YEPG at 37°C (restrictive temperature), where actin polarization and bud formation did not occur. At 30-min intervals, cells were fixed and stained to monitor the kinetics of nuclear division; 200 cells were scored in each sample. (B) Strains DLY657 (○), DLY690 (●), and JMY1495 (cdc24-1 SWE1 GAL:HSL1:LEU2) (□) were grown at 24°C in YEPS (noninducing nonrepressing medium for the GAL promoter) and arrested in G₁ phase with α-factor. Galactose was then added to induce the GAL promoter, and 1 h later the cells were released into fresh YEPG at 37°C and monitored as described above.