FIG 3.

HWP1 expression in double heterozygous deletion strains showing negative and positive genetic interactions. The expression of HWP1 in the indicated strains in 48-h in vitro biofilms was assessed by RT-PCR as described in Materials and Methods. The dashed line indicates the fold change in HWP1 expression if the two TFs functioned independently and thus displayed no genetic interaction. (A) The brg1Δ/BRG1 efg1Δ/BRG1 strain shows a negative genetic interaction during OPC infection and a negative genetic interaction with respect to biofilm HWP1 expression. (B) Regulatory circuit consistent with the effect of TEC1 and BCR1 mutations on HWP1 expression. Arrows indicate activating interaction; cross bar indicates deactivating interaction. (C) The tec1Δ/TEC1 brg1Δ/BRG1 strain shows a positive genetic interaction during OPC infection and a positive genetic interaction with respect to HWP1 expression. (D) Regulatory circuit consistent with the effect of BRG1 and EFG1 mutations on HWP1 expression. The data are presented as the means of 3 to 4 independent replicates performed in triplicate with standard errors of the means. Differences between mutants were analyzed by one-way ANOVA followed by Student's t test to assess significance of individual group differences (P < 0.05).