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(131) Effects of genotoxicants at the population level of fish - Results of complete life cycle tests with zebrafish (Danio rerio). Diekmann, Markus1, Hultsch, Veit1, Waldmann, Petra2, Schnurstein, Andreas3, Grummt, Tamara4, Braunbeck, Thomas3, Nagel, Roland1, 1 2 3 4 ABSTRACT- The genotoxic potential of environmental pollutants may be identified in surface waters by means of various genotoxicity assays. Whereas identification of genotoxins is usually conducted with regard to the potential impact on man, effects on populations of aquatic organisms such as fish are still not clear. Therefore, complete life cycle (CLC-) tests with zebrafish and two model genotoxicants, benzo[a]pyrene (BaP) and 4-nitroquinoline-1-oxide (4-NQO), were performed. In these tests, the F1-generation of zebrafish was continuously exposed from fertilized eggs until sexual maturity. After investigations of effects in reproduction of the F1-generation, effects on the F2-generation were studied over a period of six weeks. Concomitantly, adult F1-fish were investigated with respect to genotoxicity by the following assays: UDS-test (unscheduled DNA synthesis), comet assay (alkalilabile sites as well as single and double strand strand breaks), alkaline filter elution (strand breaks), as well as micronucleus test (secondary DNA damage such as deletions). The assessment of the ecotoxicological relevance of the genotoxic potential was made by correlation with population-relevant effects detected in the life cycle tests. Due to its physical properties, only environmentally relevant BaP-concentrations from 3, 7, 18, 64, and 193 ng/L, respectively, could be achieved. In the life cycle test, only retardation of egg production of the F1-generation could be detected. With regard to genotoxicity, only sporadic strand breaks were detected. The concentrations of the model genotoxicant 4-NQO were 0.1, 0.3, 1.1, 2.9, and 14.6 Key words: zebrafish, life cycle test , (eco-)genotoxicity , population |
g/L. Whereas at 14.6