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2L (1) - Immunotoxicity - genotoxicity - ED (TH8/4) Can genetic techniques improve the sensitivity and accuracy of regular ecotoxicity tests? Breitholtz, Magnus1, Ehn, Emma2, Gorokhova, Elena3, Gilek, Michael2, Grahn, Mats2, Bengtsson, Bengt-Erik1, 1 Institute of Applied Environmental Research, Stockholm University, Stockholm, Stockholm, Sweden2 Södertörn University College, Huddinge, Stockholm, Sweden3 Department of Systems Ecology, Stockholm University, Stockholm, Stockholm, Sweden ABSTRACT- It is recommend that Environmental Risk Assessment should rely on tests that (a) identify population-level endpoints and (b) focus on the entire life cycle of test organisms. Besides being ecologically relevant, the tests should also be general, accurate and cost-effective. We have earlier studied effects of single substances (e.g. synthetic musks and flame-retardants) on development, reproduction and population growth rate in the harpacticoid copepod Nitocra spinipes. In these experiments the larval development rate, which was recorded after 6-7 days, was more sensitive than the population growth rate, which was recorded after an additional 20 days exposure. However, the stable size of the treated populations probably depended on increased reproduction rates of genetically more tolerant females. If so, the seemingly unaffected populations consisted of individuals, which originated from a relatively small set of females. Hence, the genetic diversity within these populations could have been reduced compared to the control populations. Decreased genetic diversity may result in gross implications for wild populations, especially if abiotic and biotic conditions change as well. To shed some light on these issues, we are currently adopting established genetic methods, i.e. amplified fragment length polymorphism (AFLP) as well as amplification of ribosomal and mitochondrial DNA, which we will use in experiments to compare differences and changes in genotype and genetic variability between (a) different strains of N. spinipes and (b) pollution exposed and unexposed laboratory and environmental populations. This will provide genetic data along with population-level ecotoxicity data from the same test. Key words: copepod, ecotoxicity test, DNA, AFLP |
