RNA-mediated gene silencing in monokaryons and dikaryons of Schizophyllum commune.

Disruption of genes by homologous recombination occurs at a low frequency in the basidiomycete Schizophyllum commune. For instance, the SC3 and SC15 genes were inactivated at frequencies of 1 and 5%, respectively. As an alternative to disruption, we used gene silencing through the introduction of a hairpin construct. The SC15 gene, which encodes an abundantly secreted structural protein, was silenced at a frequency of 80% in monokaryons of S. commune after introduction of a hairpin construct of the gene. Silencing also occurred in dikaryons in which one of the partners was not a silenced strain. The silencing mechanism resembles RNAi in other filamentous fungi and is a powerful tool for the functional analysis of genes expressed in monokaryons or dikaryons.