The mutagenic activity of hydroxyurea in Chlamydomonas reinhardi

Aneuploidy and other genetic effects induced by hydroxyurea in Saccharomyces cerevisiae

Hydroxyurea induces mitotic gene conversion, mitotic crossing-over, reverse mutation, respiration-deficient petite mutants and aneuploidy in growing cultures of Saccharomyces cerevisiae. Evidence is presented indicating that induction rather than selection is responsible for the increase in frequency of the genetic end points measured. Complications concerning the detection of aneuploidy in the presence of other genetic effects are described, and the need for following the complete protocol for confirmation of the aneuploids in any chemical screening program is emphasized.

The effect of spermine on spontaneous and UV-induced mutations in Schizosaccharomyces pombe

The effect of different concentrations of spermine on spontaneous and UV-induced mutation in the adenine forward mutation system of Schizosaccharomyces pombe was investigated. The effect of spermine on spontaneous mutation was studied in 5 mutator strains (mut 1-4, mut 1-23, mut 2-9, mut 2-20 and mut 3-21) and on UV-induced mutation in a pigmented adenine-requiring strain and its radiation-sensitive derivative (rad 13). The effect of spermine exposure on mutation induction before and after UV irradiation was also investigated. Spermine increased spontaneous forward mutation in the mut 1-4 strain by 47%, and enhanced UV-induced forward mutation 2-fold in the rad 13 and normal pigmented strains. No antimutagenic effect of spermine was seen in any of the strains tested. This is in marked contrast to the antimutagenic effect of spermine observed with bacteria.