A characteristic hallmark of Aspergillus niger is the formation of black conidiospores. To understand the genetic basis of black spore formation, we have identified four genes required for pigmentation by using a complementation approach. First, we characterized a newly isolated color mutant, colA, which lacked pigmentation resulting in white conidia. Pigmentation of the colA mutant was restored by a gene (An12g03950) which encodes the A. niger ortholog of the 4’-phosphopantetheinyl transferase protein (PptA). The loci giving rise to fawn, olive, and brown color phenotypes were identified by complementation. The fawn mutant was complemented by the polyketide synthase A protein (PksA, An09g05730), the ovlA mutant by An14g05350 (OlvA) and the brnA mutant by An14g05370 (BrnA), the respective homologs of pksP/alb1, ayg1 and abr1 in A. fumigatus. Targeted disruption of the four genes confirmed the complementation results. Epistasis was determined for pksA, olvA and brnA by constructing double mutants. This set of isogenic color mutants is a useful tool to do classical genetic analyses in Aspergillus niger.
Full conference title:
26th Fungal Genetics Conference
- Fungal Genetics Conference 26th (2005)