GENOTOXICITY OF POLYCHLORINATED-BIPHENYLS (PCBS) - RECOMBINOGENESIS BY BIOTRANSFORMATION PRODUCTS

A coplanar polychlorinated biphenyl (PCB) when eaten by test animals i ncreased the rate of recombination in somatic cells, indicating a new mechanism of action for these compounds. Using the eye-mosaic test a h igh bioactivation strain of Drosophila that consumed 4,4'-dichlorobiph enyl (4,4'-DCB) manifested a genotoxicity rate that was three-fold gre ater than that in animals fed the solvent-spiked medium. This compound was not genotoxic in a suppressed bioactivation strain indicating tha t genotoxicity requires bioactivation of the compound. High bioactivat ion test strains made heterozygous for a paracentric inversion, a chro mosomal rearrangement that suppresses homologous recombination, exhibi ted significantly reduced genotoxicity after treatment.