Quantitative Selection of Respiratory Deficient Mutants in Yeasts by Triphenyltetrazolium Chloride

Abstract

Triphenyltetrazolium chloride exhibits a strong growth inhibition in respiratory competent cells but shows only minor effects in respiratory deficient mutants of Saccharomyces cerevisiae and Schizosaccharomyces pombe. Use of this dye thus allows rapid selection of rarely occurring respiratory deficient mutants, showing karyotic as well as extrakaryotic inheritance. Mutation induction by tetrazolium chloride was not observed. The results favour the hypothesis that triphenyltetrazolium chloride interferes with the terminal oxidase of the respiratory chain.