Mutagenic effects induced in Saccharomyces cerevisiae by breakdown products of 1-naphthylamine and 2-naphthylamine formed in an enzyme-free hydroxylation system

New Developments in Mutagenicity Screening Techniques with Yeast

“…It is also noteworthy (Fig. 4) (39). The fact that they are not mutagenic (61) indicates that the nitroso group is essential for the genetic activity of DMNA and DENA.…”

“…Malling (59,60) (63)(64)(65)(66)(67), Mayer (68) demonstrated that the breakdown products of 1-NA and 2-NA formed in the Udenfriend hydroxylation system, but not the parent compounds, were mutagenic for Saccharomyces. More recently DMNA, DENA, 1-NA, and 2-NA breakdown products have all been shown to induce mitotic crossing-over in Saccharomyces using the Udenfriend hydroxylation system (39).…”

“…The methodology has been previously reported (39,61,68). Essentially, the procedures involve simply incubating the genetic indicator organism with the test chemical in the hydroxylation medium and removing cell samples at appropriate time intervals to assay for induced genetic events.…”

“…Survival in all samples was 70% or higher. Other aromatic amines, 1-NA and 2-NA, were previously shown to induce mutation (68) and mitotic crossing-over (39) in Saccharomyces with the Udenfriend reaction medium only after breakdown in the presence of oxygen. A representative sample of sectored colonies induced by 2-aminobiphenyl, 4-aminobiphenyl, and p-toluidine were cloned for their red and white portions.…”

“…The results presented in Figures 1-3 and over data presented in this paper are de- Table 2 compare the induction of mitotic scribed by Mayer (39).…”