GENOTOXIC POTENCY IN DROSOPHILA-MELANOGASTER OF SELECTED AROMATIC-AMINES AND POLYCYCLIC AROMATIC-HYDROCARBONS AS ASSAYED IN THE DNA-REPAIR TEST

Drosophila melanogaster stock consisting of meiotic recombination defi cient (Rec ) double mutant mei-9a mei-41D5 males and Rec+ females was exposed at the larval stage to an aromatic amine or a polycyclic aroma tic hydrocarbon. After emergence as adult flies, the males and the fem ales were scored separately. When the treatment caused a dose-dependen t reduction in the male to female ratio from the control level, the ex periment was repeated with a larval stock consisting of Rec+ males and Rec+ females under comparable conditions. A preferential killing effe ct upon Rec- larvae was taken as evidence of DNA damaging effect of th e test compound. Among 16 compounds tested, I-AP, B(a)P, 2-AF, DAF, 4- AAF, 2-AAF, I-AA, 2-AA, DMA, B(a)A and DMBA were registered as positiv e; Py and 3-MC were weakly positive; and B(e)P, Fluo and Ant were nega tive. The selective killing effects of the compounds in each of the py rene, fluorene and anthracene series varied drastically as a function of structure in a way similar to that reported for the genotoxicity in Drosophila and the carcinogenicity in rodents. The Drosophila DNA rep air assay will serve as a simple adjunct to the already available mean s for studying the genotoxic potency of aromatic amines and polycyclic aromatic hydrocarbons.