Genotoxic hazard of pollutants in cetaceans: DNA damage and repair evaluated in the bottlenose dolphin (Tursiops truncatus) by the Comet Assay.
Single cell gel electrophoresis (or Comet Assay) was used for evaluation of the in vitro genotoxicity of hydrogen peroxide (used as a positive control), polychlorinated biphenyls (PCBs) (Aroclor 1254) and methyl mercury chloride, in isolated bottlenose dolphin leukocytes. Results showed that hydrogen peroxide and methyl mercury induced DNA strand breakage in a dose-dependent manner, while PCBs did not induce a clear dose-effect response at the low doses investigated. Efficiency in repairing DNA breakage induced by methyl mercury was also evaluated. Findings demonstrated that dolphin cells are characterized by higher efficiency in DNA repair when compared to human leukocytes. The observed resistance to methyl mercury toxicity in dolphins was hypothesized to be a defence strategy developed to combat high dietary exposure and compensate for limited capacity to excrete persistent pollutants.
Taddei
F
F
Dipartimento Morfologia Umana e Biologia Applicata, Università di Pisa, Via Volta 4, I-56126 Pisa, Italy.
Scarcelli
V
V
Frenzilli
G
G
Nigro
M
M
D000818:Animals; D020552:Comet Assay; D004249:DNA Damage; D004260:DNA Repair; D004289:Dolphins / Q000235:genetics / Q000502:physiology; D006861:Hydrogen Peroxide / Q000633:toxicity; D008297:Male; D008767:Methylmercury Compounds / Q000633:toxicity*; D016877:Oxidants / Q000633:toxicity; D011078:Polychlorinated Biphenyls / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity
D008767:Methylmercury Compounds; D016877:Oxidants; D014874:Water Pollutants, Chemical; D006861:Hydrogen Peroxide; D011078:Polychlorinated Biphenyls