Induction of rho-minus mutants in Saccharomyces cerevisiae by guanidine hydrochloride. I. Genetic analysis

Abstract

Guanidine hydrochloride (GuHCl) induced in Saccharomyces cerevisiae cytoplasmic petite mutants (rho-) of the suppressive type. However, it was unable to induce the neutral type, even after prolonged incubation or increased drug concentration. No correlation was found between the degree of suppressiveness and the time of incubation of yeast cells with guanidine hydrochloride. The suppressiveness of rho- induced was not altered by further treatment with GuHCl, whereas it was reduced upon treatment with ethidium bromide (EtBr). Some mitochondrial genetic information was lacking in the rho- mutants induced by GuHCl, as demonstrated by the loss of the gene for erythromycin resistance and by reduced buoyant density of mitochondrial DNA of some rho-. There was no correlation between the degree of suppressiveness of the rho- induced by GuHCl and the buoyant density of the mutant mitochondrial DNA.