Manganese mutagenesis in yeast: II. Conditions of induction and characteristics of mitochondrial respiratory deficient<i>Saccharomyces cerevisiae</i>mutants induced with manganese and cobalt

Abstract

SUMMARY Manganese and cobalt are capable of inducing ρ − mutations* in non-growing cells of Saccharomyces cerevisiae , but their mutagenic action is much stronger in growing cells. At a given concentration cobalt and manganese can be either strongly mutagenic or non-mutagenic, depending on the cell density. Most of the ρ − mutants induced with manganese and a considerable proportion of those induced with cobalt are suppressive and/or transmit drug resistance markers, so they must still carry mitochondrial DNA. Cobalt can decrease suppressiveness with low efficiency and eliminate drug resistance markers from established ρ − clones.