Effect of irradiation and mutagenic chemicals on the generation of ADH2-constitutive mutants in yeast. Significance for the inducibility of Ty transposition.

Mutations caused by the insertion of a Ty element resulting in an antimycin-A-resistant phenotype in an adh1- strain of Saccharomyces cerevisiae were used as an assay for the quantitative detection of Ty transposition. Antimycin-A-resistant mutants were found to be inducible by ethyl methanesulfonate (EMS) as well as by gamma- and UV irradiation. DNA analysis of gamma-induced mutants showed an increase of the fraction of Ty insertions in the ADH2 locus with increasing dose.