Methionine as an antimutagen in Schizosaccharomyces pombe

Abstract

Methionine inhibition of the phenotypic expression of adn - → adn + reverse mutations in the fission yeast Schizosaccharomyces pombe was investigated. This inhibition occurred solely with L-methionine, and not with a variety of other growth factors. The inhibitory effect on revertant expression did not apply to a number of reverse and forward mutations other than adn - → adn +. Alteration of the adenine supply to adn - organisms before and after mutagen treatment had no effect. Methionine was shown to have additional inhibitory effects on the leakiness of an adn - mutant, on complementation between adn-1 mutants, and on the growth of certain adn - strains in the presence of the analogue 6-methyl-aminopurine. It is suggested that S-adenosylmethionine may be implicated in these methionine effects.