Regulation of Fruiting Body Formation in Coprinopsis Cinerea

Fruiting body formation in the edible dung fungus Coprinopsis cinerea is regulated by environmental cues (nutrients, temperature, light, humidity), physiological conditions (mycelial status, age) and genetic control elements (e.g. A and B mating type genes, dst1 and dst2 genes for light regulators). Fruiting body development consists of a series of defined steps occurring in a concerted process over seven days. Following hyphal aggregation, stipe and cap tissues differentiate under the control of light and dark phases. Once light-induced karyogamy takes place in basidia present at the surface of the gills in the cap of mature primordia, stipe elongation and cap expansion start parallel to meiosis in the basidia and subsequent basidiospore formation. All these processes are expected to appoint numerous intracellular as well as extracellular protein functions, many of which might be specific to steps in fruiting. Since the genome of the fungus is available, identification of proteins can now be addressed by large scale proteomic techniques. In order to gain an insight into participating proteins from a first analysed developmental step, we collected immature fruiting bodies after meiosis II. Stipe and caps were separated from each other, and intraand extracellular proteins from both types of samples were isolated and compared by 1Dand 2D-gel electrophoresis. Whilst there might be contaminating intracellular proteins in the extracellular fractions, there are many proteins not present in the intracellular fractions. Stipe and cap fractions clearly differed from each other, less so in the intracellular and strongly in the extracellular proteome.