Fig. 1.

Model for transcriptional regulation of cellulases in β-glucosidase deletion strains of N. crassa. Both transcriptional derepression and specific induction are required to achieve maximal transcriptional activation of cellulase gene expression. Arrows indicate possible pathways for cellulose metabolites. Blue lines and red lines indicate pathways hypothesized to be minimized and to be most active, respectively, in the Δ3βG and Δ3βGΔcre deletion strains.