Fitness parameters and DNA effects are sensitive indicators of copper-induced toxicity in Daphnia magna

This study compared the effects occurring at molecular and population level s in Daphnia magna exposed to copper concentrations in the range of 15-120 mug/l. The qualitative and quantitative modifications arising in random amp lified polymorphic DNA (RAPD) profiles as a measure of DNA effects were com pared with a number of key ecological fitness parameters, namely, the age-s pecific survival, age-specific fecundity, net reproductive rate, and intrin sic rate of population increase. Results suggested that growth, reproductio n, and most of the fitness parameters as well as genomic template stability (a qualitative measure reflecting changes in RAPD profiles) were significa ntly affected at copper concentrations of 90 and 120 mug/l. Among the fitne ss parameters, the age-specific fecundity and net reproductive rate were th e most sensitive parameters of toxicity. Changes in RAPD patterns generally occurred at copper concentrations of 90 and 120 mug/l, but with one primer , changes significantly arose at all copper concentrations. Overall, molecu lar and population parameters compared well and represented a sensitive mea ns to measure toxicity induced by copper in Daphnia magna. In conclusion, t he measurement of parameters at both molecular and population levels is val uable for investigating the specific effects of agents interacting with DNA . Ultimately, this methodology may allow the ecotoxicological examination o f the link between molecular alterations and measurable adverse effects at higher levels of biological organization.