Fig. 5

Comparison of PfopA and the constitutive promoter PgpdA from A. nidulans for enhanced green fluorescent protein (EGFP) expression in A. niger. A Observation of EGFP fluorescence of EGFPPfopA and EGFPPgpdA grew on the MM-sucrose and MM-glucose plates. Images in DIC and fluorescence channels were acquired at 40 × magnification and 600 ms exposure using a Nikon positive fluorescence microscope. The scale bar is 20 μm. B RT-qPCR monitoring of egfp expression levels under the control of PfopA and PgpdA at different sucrose concentrations. Actin was used as the reference gene. The 2^−ΔΔCt method was used for calculating relative expression levels. C Quantitative analysis of EGFP fluorescence intensity of EGFPPfopA and EGFPPgpdA at different sucrose concentrations. Values and standard deviation (SD) of triplicates are presented in the figure. Asterisks indicate statistically significant differences (**p < 0.01) as assessed by Student’s t test. n.d., not detected