Monitoring the mating-type-driven transcriptomes of Aspergillus fumigatus

Sexual identity of the human pathogenic mold Aspergillus fumigatus is determined by the mating-type idiomorphs MAT1-1 and MAT1-2 residing at the MAT locus. Given that the MAT1 gene products are DNA binding master regulators that govern fruiting body formation, the MAT1-driven transcriptomes of A. fumigatus were monitored by conditional overexpression of either MAT1 gene followed by RNA-seq analyses. Overexpression (OE) of either mating-type factor was achieved by replacing the original promoter by a heterologous one (pxylP) that is conditionally active in the presence of xylose as sole carbon source. Strains were pre-grown in liquid cultures before shifting the fungal mycelia to inducing, xylose-containing culture medium. Two sets of strains were compared with the MAT1-1 and MAT1-2 wild-type (WT) progenitors D141 and Af293, respectively, serving as control samples that were compared to the recombinant OE strains AfS146 [pxylP::MAT1-1] and AfS147 [pxylP::MAT1-2], respectively. Two biological replicates per strain were generated, yielding eight samples that were evlauted a by case (OE) vs. control (WT) analysis for differentially expressed genes.