HETEROCARYOSIS OBSERVED IN RHIZOPUS JAVANICUS

Abstract

By plating spores of two auxotrophic mutants of Rhizopus javanicus on a medium supplemented with limited amounts of nutrients, heterocaryotic colonies were obtained in frequencies of 10^-4 to 10^-5. Upon formation of spores, eighteen of the colonies gave spores of both component types (mycelium-type heterocaryons), while one gave, besides spores of component types, prototrophic spores (spore-type heterocaryons). The prototrophs segregated the three types repeatedly, in no case giving rise to a recombinant.