Fig. 3
From: HisB as novel selection marker for gene targeting approaches in Aspergillus niger
Schematic overview of the hisB disruption approach in A. niger and subsequent counterselection. The plasmid pMF22.1 was constructed via amplifying parts of the hisB gene and its 3’ region (numbers above the fragments indicate the DNA position from the start codon). Both fragments were inserted via Gibson cloning into the BsrGI linearized plasmid pAO4-13 carrying the Aspergillus oryzae pyrG [32] giving rise to the plasmid pMF22.1. The plasmid was transformed into the strain MA169.4 [15] thereby disrupting the hisB locus giving rise to MF40.6. Counterselection may either lead to a genomic rearrangement, thereby eliminating the plasmid via recombination in its hisB locus or the 5’ region, creating a truncated hisB* (MF41.3) or wildtype hisB loci, respectively