The overall goal of this project is to investigate the role of putative metacaspase genes in the fungus Schizophyllum commune by means of gene knockout experiments. We have utilized a strain of S. commune which has had its Ku80 gene knocked out, rendering it unable to integrate DNA via the non‐homologous end joining pathway. This forces transformants to integrate homologously, as required for gene knockout. The gene Scp1 encodes a likely metacaspase, proteins suspected to have activity similar to members of the caspase protein family. A non‐functional version of Scp1 was previously generated by inserting a gene that confers the ability to synthesize tryptophan (Trp1) into the Scp1 coding region. This knockout construct was transformed into a Trp‐, ΔKu80 strain of Schizophyllum commune. It was observed that while some S. commune colonies grew at the rate expected of a typical strain, others took about ten days to become macroscopically visible. It is anticipated that we will be able to confirm the presence of Scp1 knockouts via PCR, and then examine these strains for perturbations in mushroom development. This process of generating knockout constructs and transforming them into S. commune will be carried out for other genes, including the other members of the metacaspase family. Support from a Davenport Summer Research Fellowship is gratefully acknowledged.