FIG 2.
SomA mediates cell wall stress-induced biofilm formation. (A) Crystal violet staining of 24-h-old biofilms of the indicated mutant strains compared to that of the A. fumigatus parental wild-type A1160C (WT) grown in the presence of a range of concentrations of CFW. (B) Crystal violet staining of 24- and 36-h-old biofilms of the conditional Tet-somA mutant grown in the presence of a range of concentrations of CFW. The expression of somA was induced by supplementing the culture media with 1 μg/ml doxycycline. (C) Scanning electron micrographs of the Tet-somA mutant hyphae in the presence or absence of 12.8 μg/ml CFW and/or 1 μg/ml doxycycline. Scale bar, 1 μm. (D) Heat map analysis of the relative expression level of the GAG gene cluster in the Tet-somA mutant (ON and OFF) under CFW cell wall stress condition. The Tet-somA mutant was first cultured in MM with or without doxycycline for 22 h. CFW at a final concentration of 100 μg/ml was then added to the media, and gene expressions were measured at 0.5, 1, and 2 h, respectively. Gene expression was normalized to the endogenous reference gene tubA, and expression was reported relative to the unstressed Tet-somA (ON) condition at 22 h growth. All the results were performed by three independent biological experiments.