Fig. 4

Expression analysis of genes surrounding the polyporic acid synthetase gene acyN. a Scheme of the genomic situation in strain NRRL 50072. Gene IDs: 6104 = Glycosyl hydrolase; 6105 = Phosphatidic acid-preferring phospholipase A1; 6016 = 3-Desoxyarabinoheptulosanate-7-phosphate (DAHP) synthase; 6107 = Fungal specific transcription factor (zinc ion binding); 6108 = NRPS-like enzyme with C-terminal thioesterase domain (AcyN); 6109 = Ribosomal protein L1 (intergenic region between 6108 and 6109 ~ 7 kb). b Semiquantitative RT-PCR analysis of genes 6103 to 6109 normalised against beta-tubulin gene expression levels. cDNA was generated from A. sarcoides strain (CBS 247.80) grown on either ascocorynin inducing potato dextrose broth (PDB) or non-inducing Aspergillus complete medium (ACM). Strain S1C was isolated from fruiting bodies of a strain found growing on birch wood in Nottinghamshire (UK, see also Fig. 2) and was cultivated on PDB medium only. Genomic DNA (gDNA) served as PCR control. The putative transcription factor (TF, gene ID 6107) shows basal unspliced constitutive expression. The spliced product (*) is only observed under inducing conditions. Only the genes coding for the DHAP synthase, the transcription factor and AcyN show an expression pattern that correlates with ascocorynin production