Figure 4.

The EXA3–1 mutation in the gene encoding HSF prevents G₁ arrest upon both temperature up-shift and AZC treatment. Midlogarithmic cultures of DS10 (WT) and the congenic EXA3–1 mutant (MH297) growing in YPD at 23°C were subjected to a temperature up-shift (TU: 23°C to 37°C). Midlogarithmic cultures of the same strains growing in YPD at 30°C were treated with AZC (50 mM) at t = 0 without a temperature change. The percentage of unbudded cells was determined for each culture as a function of time after treatment was initiated.