The ichijiku1 (ich1) gene is an essential controller of the formation of the ‘cap’, or pileus in the fruiting of Coprinopsis cinerea, an edible mushroom more commonly known as grey shag. The ich1 gene encodes for the Ich1 protein, a methyltransferase enzyme with a winged helix-like DNA-binding domain as well as an o-methyltransferase domain. These structural features contribute towards its rather unique molecular mechanisms. Formation of the pileus represents a crucial part of the reproductive process of C. cinerea. Thus, mutations or environmental conditions that affect pileus formation are likely to have a dramatic impact on the survival of such strains of the fungus. Dr Hajime Muraguchi, from Akita Prefectural University is leading a team that is seeking to elucidate the molecular mechanisms of the ich1 gene.