Genetic activity of trichloroethylene in yeast

Trichloroethylene (TCE) was tested for its ability to induce both point mutation and mitotic gene conversion in diploid strain of yeast. Saccharomyces cerevisiae (strain D7) was tested for both activities in culture with and without a mammalian microsomal activation system and in the intrasanguineous host-mediated assay in mice. Strain D4 (gene conversion) was tested only in the host-mediated assay. In suspension tests with D7, TCE was toxic but not genetically active without microsomal activation. When a mouse liver 10,000 xg supernatant was included in the suspension tests, dose related increases in both mutation and gene conversion were seen at survival levels of greater than 50 percent. In the host-mediated assay, TCE induced both point mutation and gene conversion in D7 and gene conversion in D4 when recovered from the liver and kidneys after both acute and subacute dosing. Yeasts recovered from the lungs showed little, if any, increase in either point mutation or gene conversion.