Figure 1. Induction of white-opaque switching by the hyperactive STE11 ^ΔN467 allele in the wild-type strain WO-1 and the indicated mutants.

White cells of the strains were grown for 18's medium at 30°C in the presence of doxycycline to induce expression of the STE11 ^ΔN467 allele, diluted, and plated on Lee's agar plates without doxycycline to determine the percentage of opaque (black bars) and mixed white/opaque colonies (gray bars). Two independently constructed strains were tested in each case; the untransformed parental strain WO-1 served as control. Results are the means and standard deviations from three biological replicates. Only background switching frequencies were observed in all strains when the precultures were grown in the absence of doxycycline (not shown).