The human pathogenic fungus Aspergillus fumigatus is known to produce various spore-borne natural products. One of these is the polyketide trypacidin which has been shown to be involved in the interactions with alveolar macrophages as well as with the amoeba Dictyostelium discoideum. Even though recent studies could elucidate the corresponding gene cluster in A. fumigatus, it still remained elusive why several isolates do not produce trypacidin. We addressed this question employing a CRISPR/Cas9-based gene editing strategy. Thus, we could link a single nucleotide insertion in the polyketide synthase of the trypacidin biosynthetic pathway and also reconstitute its production in a nonproducing strain. In addition, we developed a split-marker approach for the selection of edited strains, since the selectable marker could not be directly linked to the target site. The here established tool could be useful in next generation fungal genetics e.g. for the investigation of single nucleotide polymorphism, or amino acid substitutions.
Full conference title:
- Asperfest 14 (2017)