FIG. 1.

Long-term memory at GAL genes requires Gal1p but not SWI/SNF. The schematic at the top depicts a regimen of growth in different carbon sources. Gal, 2% galactose; Glc, 2% glucose. (a) RT-PCR analysis of GAL10 mRNA levels following initial induction and reinduction after long-term glucose repression (12 h). The wild-type (WT) culture showed a memory of previous GAL10 induction, which was lost in the gal1Δ strain. (b) RT-PCR of GAL1 and GAL10 mRNA levels from the swi2Δ strain. The reinduction of GAL1 and GAL10 is fast compared to initial induction following long-term glucose repression (12 h). Data were averaged over three independent experiments and are represented as relative fold increases over ACT1 mRNA normalized to a maximum value of 1. Error bars represent standard deviations at each point.