Fig 7. ZfpA mediates echinocandin tolerance by altering developmental chitin synthesis.

(A) Images represent calcofluor white (CFW) staining of WT CEA10, ΔzfpA, and OE::zfpA following overnight exposure to 1 μg/mL caspofungin (CSP) or DMSO. CFW staining is represented by cyan and cytoplasmic RFP signal is shown in magenta. Scale bar = 50 μm. (B) Experimental setup for chitin stimulation with CaCl₂/CFW. Spores were incubated for 8 h at 37°C or until germination in liquid GMM or liquid GMM supplemented with 0.2 M CaCl₂ and 100 μg/mL CFW. After germination, media was replaced for GMM + 1 μg/mL caspofungin or DMSO and hyphae were incubated for an additional 12 h before detecting PrestoBlue viability reagent signal in a plate reader. (C) Bars represent mean±s.d. of relative fungal viability following caspofungin exposure. Relative viability was calculated by normalizing the mean signal of caspofungin-treated wells to the mean signal of DMSO-treated wells. All experiments included 5 wells/condition. Data are pooled from 3 independent experiments. p values calculated by ANOVA with Sidak’s multiple comparisons. **p<0.01,***p<0.001.