ISOLATION OF SUPPRESSIVE SENSITIVE MUTANTS FROM KILLER AND NEUTRAL STRAINS OF SACCHAROMYCES CEREVISIAE

1 Department of Biology, McGill University, Montreal, Canada

Dominant sensitive mutants were isolated from a killer and a neutral strain of Saccharomyces cerevisiae by treatment with nitrosomethylurethane. Genetic studies suggest that these sensitives arose by mutation of the wild-type cytoplasmic genetic determinants (k) or (n) to a mutant form (s). (s) determinants lack wild-type (k) and (n) activity but are retained in the cell and suppress the replication or activity of the wild-type determinants, converting killer and neutral cells to the sensitive phenotype. These mutants show an obvious similarity in behavior to suppressive petite mutants of yeast.

Submitted on February 6, 1973
Revised on April 15, 1973