Investigations of aneuploidy-inducing chemical combinations in Saccharomyces cerevisiae.

For several years we have been investigating combinations of chemicals for their ability to induce aneuploidy. Earlier published results indicated that combinations of certain chemicals showed a potentiation effect while other combinations did not. We have continued to explore this phenomenon and report additional findings in this communication. Combinations of ethyl acetate and methyl ethyl ketone showed a potentiation effect as did 1-methyl-2-pyrrolidinone-nocodazole combinations. Combinations that did not show a potentiation effect were 2-pyrrolidinone-nocodazole and 1-methyl-2-pyrrolidinone-ethyl acetate. We also found that nocodazole, which is a potent inducer of aneuploidy in yeast extract-peptone-dextrose (YEPD) medium but not in synthetic complete (SC) medium, showed a potentiation effect with ethyl acetate in SC medium. This effect in SC medium is similar to that previously reported for nocodazole with ethyl acetate in YEPD medium. When nocodazole was dissolved in 1-methyl-2-pyrrolidinone as a concentrated stock solution, a potentiation effect occurred even at low concentrations of the solvent.