Mutation of a heterothallic strain to homothallism.

Upon mutagenesis, a heterothallic alpha-alpha diploit strain mutated to homothallism. The gene confering homothallism is nuclear, recessive, and unlinked to mating type. This gene is not allelic to the HO gene, which is responsible for previously described instances of homothallism in yeast. We have designated this new gene for homothallism as cmt (change of mating type).