Microbial mutation studies with tetrachlorvinphos (Gardona)).
The mutagenic activity of tetrachlorvinphos was investigated in agar-layer cultures of Escherichia coli WP2 and WP2 uvrA, Salmonella typhimurium TA1535, TA1538, TA98 and TA100. Assays were carried out both in the presence and in the absence of S9 fractions of liver homogenates from rats and mice, both from untreated animals, and from animals pre-treated with Aroclor 1254. The induction of mitotic gene conversion by tetrachlorvinphos was studied in stationary phase cultures of the yeast Saccharomyces cerevisiae D4. No mutagenic effects, as determined by reverse gene mutation, were detected in vitro in the bacterial/mammalian microsome assay when a range of bacterial tester strains were exposed to tetrachlorvinphos at amounts up to 2000 micrograms per plate, either in the absence or in the presence of S9 fractions from non-induced or Aroclor-induced mouse or rat livers. Tetrachlorvinphos did not increase the mitotic gene conversion frequency in stationary phase cultures of the yeast, Saccharomyces cerevisiae D4.