Petite and sectored induction in Saccharomyces cerevisiae by propidium iodide: synergistic effect of sodium dodecyl sulfate.

Sodium dodecyl sulfate (SDS) was examined for its effect on petite and sectored colony induction in Saccharomyces cerevisiae by propidium iodide (PI) and ethidium bromide (EB). 4-h cultivation with 100 microM PI and 100 micrograms/ml SDS resulted in virtually all plated cells growing as sectored colonies with no decrease in viability. Sectored colonies are mixed colonies comprised of respiratory deficient and competent cells believed to be derived from an unstable respiratory deficient cell. Further cultivation with PI and SDS prior to plating led to induction of complete petite colonies with a rapid decrease in viable cells. PI alone at this concentration exhibited weak induction of sectored colonies (maximum 12.3% at 8 h) and petite colonies (maximum 10.8% at 12 h), but SDS alone caused induction of neither. 50 microM PI had almost the same activity as 100 microM except for a delay in the induction of sectored colonies in the initial stage, and a decreased rate of petite colony induction. The effects of 20 microM PI and SDS were much lower than that by 50 microM and no inhibition of growth was observed. 10 microM PI was quite inactive even in the presence of SDS. Under resting conditions, 10 approximately 100 microM PI and 100 micrograms/ml SDS induced about 60% sectored colonies at 12 h incubation and more than 60% petite colonies at 24 h. After 6 h incubation, decrease in survival was also observed.