FIG. 1.

Phenotypes of revertant CEM-2. (a) Genealogy of CEM-2. The relevant genotypes are shown. (b) Growth of wild-type strain SC5314, the phr2Δ mutant CFM-2, and the revertant CEM-2 after 48 h of incubation on YNB at pH 4.0 and 30°C. (c) Morphology of the indicated strains 3 h postinoculation into medium 199 at pH 4.0 or pH 8 and 37°C. (d) PHR1 expression as a function of ambient pH. RNA was isolated from the indicated strains cultured in medium 199 at the pH indicated below the panels. The upper panel shows the Northern blot hybridized with PHR1. The lower panel shows the corresponding ethidium bromide-stained agarose gel prior to blotting.