FIG. 6.
Gal3p coinducer overexpression leads to rapid GAL1 induction in the wild type. (a) GAL3 mRNA expression compared between growth in raffinose and that in galactose for the indicated strains and shown as fold induction over ACT1. (b) Northern analysis using the short-term memory regimen for wild-type cells transformed with the control plasmid (left) and a Gal3p-overexpressing plasmid (PADH1-GAL3) (right). (c) Same as panel b for the swi2Δ strain. The constitutive expression of Gal3p rapidly activates GAL1 transcription even upon initial induction in the wild type. The overexpression of Gal3 uncovers a more prominent role for SWI/SNF during the initial round of induction. All Northern blots were subsequently probed for ACT1 as a loading control.