Figure 6. Time-course effect of temperature upshift on mRNA levels.

Wild-type cells were grown in YPD medium at 24 °C to reach an A₆₀₀ 0.5. The temperature was then abruptly shifted to 37 °C by transferring the culture to a new flask containing an equal volume of YPD medium that had been prewarmed to 49 °C. Results are the means±S.E.M. of mRNA molecules/pg of total RNA. Data at 0 min represent the steady-state levels in cells before the temperature upshift. No time-related effect was noted in these control cells for the full 90 min of chase. The Figure shows those mRNAs for which statistically significant increases or decreases were observed at a given time after the temperature upshift. For each transcript, the maximal fold variation is given in parentheses.