Monitoring of freshwater pollution effects through measurement of dna damage and cytochrome p4501a induction in chub (leuciscus cephalus) from the river rhone (france)
Suivi de la pollution grâce à la mesure des dommages à l'ADN et l'induction du cytochrome P450 1A chez le chevaine (Leuciscus cephalus) du Rhône
Résumé
The in vivo response of freshwater fish exposed to pollutants was assessed using two biomarkers, 7-ethoxyresorufin-O-dealkylase (EROD) induction and DNA single strand breaks. Chub (Leuciscus cephalus) were caught in spring and in fall at various locations in the Rhône river watershed. EROD activity was measured in the liver while DNA damage was evaluated in chub erythrocytes using the recently developped Comet assay. Chemical contamination was evaluated both in fish muscle (PCBs) and in sediment (PCBs, PAHs, heavy metals) collected at each sampling station. The EROD specific activity as well as the DNA damage were found to be higher in the mostly contaminated stations compared to the reference one. Sex of individuals was shown to influence the level of EROD induction but not the level of DNA damage. This study shows that multibiomarker-based approach provides complementary informations about early effects in feral fish exposed to complex chemical pollution and highlights the interest of the Comet assay in genotoxicity assessment.
Nous avons évalué les effets de la pollution sur deux biomarqueurs mesurés chez le chevaine péché dans le Rhône : l'induction de l'activité EROD et les cassures simple brin d'ADN (essai des comètes). L'activité EROD et les dommages à l'ADN sont plus importants pour les deux stations les plus contaminées. Une telle approche multi paramétrique est des plus essentielles.