Figure 5. Rbf1 is required and sufficient for expression of b-dependent genes.
The bE1 and bW2 genes were induced in strains AB31 or AB31Δrbf1; as a control for both strains, the incompatible bE2 and bW2 genes were induced in AB32. Strain CP27 (a2 Δb:: Pcrg1:rbf1) was used for induced expression of rbf1, with strain JB2 (a2Δb) as control. Induction was performed by shifting the cells from array medium containing 1% glucose to array medium containing 1% arabinose. Cells were harvested at the given time points, RNA was extracted and used for microarry-analysis (Affymetrix MPIUstilagoA gene chip). The heat-map indicates the significant changes (adjusted P<0.01; change >2) in gene expression for all b-regulated genes depicted in Fig. 1 at the given time points relative to the control strains. Most genes do not show altered expression values in response to b-induction in AB31Δrbf1, indicating that rbf1 is required for the expression of the majority of b-dependent genes. In strain CP27, the induced expression of rbf1 causes the induction or repression of a large group of the b-responsive genes, indicating that Rbf1 is sufficient for the regulation of these genes. Order of genes and expression changes are given in Suppl. Table S4. Details for the statistics and filters applied are given in “Material and Methods”.