In the mushroom-forming basidiomycete Schizophyllum commune the fruiting bodies are generally only formed by dikaryotic individuals. However, monokaryotic fruiting does occur in some strains. We have identified a monokaryotic strain that forms mushrooms when grown in the light. Interestingly, this trait showed mendelian inheritance upon crossing with a reference strain that does not produce monokaryotic fruiting bodies, suggesting that only a single gene/locus is involved. In order to identify this gene we are planning to perform a bulked segregant analysis (BSA). Furthermore, the monokaryotic fruiting bodies were subjected to histological analysis to determine differences and similarities with normal dikaryotic fruiting bodies.