Isolation of recessive developmental mutants in Coprinus cinereus.

Abstract

The basidiomycete Coprinus cinereus (Fr.) Gray has several characteristics which make it suitable for developmental studies (1, 2). The development of normal dikaryotic fruit bodies can be divided into three successive steps: the formation of aggregated hyphal knots of mycelial cells, the formation of fruit body primordia, and the maturation of primordia into mature fruit bodies. A number of developmental mutants of C. cinereus were isolated from dikaryons by TAKEMARU and KAMADA, and it has been found that these mutations are dominant to the normal alleles (3). C. cinereus can normally form a fruit body after the mating between two heterothallic strains. Mutants of the incompatibility factors A and B (Amut and Bmut) have been isolated (4). The Amut Bmut strain has several features characteristic of the dikaryon including the production of mature fruit bodies, but they retain a few features typically associated with monokaryons, such as production of abundant oidia (4). By using the monokaryotic Amut Bmut oidia, which develop homokaryotic fruit bodies, we were able to isolate the recessive developmental mutants. The present communication describes the isolation of four types of recessive developmental mutants from the Amut Bmut strain.