When intact cells of Saccharomyces cerevisiae were treated with alkali cations or thiol compounds, the cells gained the ability to take up plasmid DNAs. The transformation efficiencies of yeast cells treated with alkali cations was greatly influenced by both the kind and concentration of cation used. The transformation efficiency also varied depending on the yeast strain. Polyethylene glycol was indispensable for the transformation. The uptake of plasmid DNAs into the yeast cells was found only in the presence of this polymer. Based on these results, the properties of transformation of intact yeast cells treated with alkali cations or thiol compounds were discussed.
Japan Society for Bioscience, Biotechnology, and Agrochemistry