Generation of a Ustilago maydis ade2 Mutant

The need exists to create the auxotrophic mutants for basidiomycete Ustilago maydis to allow selection of gene transformants in minimal growth media. The ADE2 gene was identified by homology with Saccharomyces cerevisiae. Adenine-requiring auxotrophic mutants were effectively created by homologous recombination in protoplasts using a standard plasmid containing the ADE2 locus interrupted by a phleomycin resistance gene, selected on standard complex media. The knockout ade2 mutant produced grows on minimal, defined medium only if supplemented with adenine.