Aspergillus nidulans WT, ΔcrzA and ΔcrzA/scrA-: Control vs. calcium pulse

The main objective was to identifiy genes related to scrA- extragenic suppression of crzA. Thus, through transcriptional profiling, we characterised the transcriptional basis of calcium tolerance in our mutant strain, ΔcrzA/scrA-. To evaluate the effect of calcium on global A. nidulans gene expression, we performed competitive microarray hybridizations using RNA obtained from the wild-type, ΔcrzA and ΔcrzA/scrA- strains before and after short pulses (10 and 30 minutes) of 200 mM calcium chloride. The experiment was further validated by real-time PCR. Two-condition experiment : A. nidulans wild-type, ΔcrzA and ΔcrzA/scrA- strains with 200 mM CaCl2 for 10 and 30 min at 30°C and 150 rpm in 25 mL YAG medium. Firstly, the strains were grown overnight at 30°C and 150 rpm in YAG medium (preculture). Afterwards, the medium was switched by a new media (25 mL) plus calcium and incubated as described above. Control condition refers to the preculture in YAG medium without further incubation.