Coprinopsis cinerea is a species of mushroom in the family Psathyrellaceae. Commonly known as the gray shag, it is edible, but must be used promptly after collecting. Coprinopsis cinerea is an important model organism for studying fungal sex and mating types, mushroom development, and the evolution of multicellularity of fungi. The genome sequence was published in 2010. It is considered to be particularly suited organism to study meiosis, due to its synchronous meiotic development and prolonged prophase.