title: Genotoxic effects of the water-soluble fraction of heavy oil in the brackish/freshwater amphipod Quadrivisio aff. lutzi (Gammaridea) as assessed using the comet assay.
abstract: Amphipod crustaceans have been widely used as invertebrate models in ecotoxicology due to their importance in the food chain. However, few studies have evaluated the genotoxic effects of pollutants in this model using the comet assay. The main obstacle to using amphipods in the comet assay is the difficulty in obtaining enough blood cells from a single individual. In this study, we evaluated the genotoxic effects of the water-soluble fraction (WSF) of heavy oil on the brackish/freshwater amphipod Quadrivisio aff. lutzi, which is common in the coastal lagoons of southeastern Brazil, using hemocytes obtained from single amphipods (without pooling) after optimizing hemolymph extraction. The comet assay revealed significantly higher DNA damage levels (2- to 6-fold higher) in treated amphipods compared to untreated ones with a sublethal concentration of 17.6 % of the WSF within 72 h of treatment. Two independent experiments confirmed an "up and down" pattern of DNA damage, measured as the % of DNA contained in the tail of the comets. Elevations in DNA damage levels were observed at the 6 and 48 h time points, while very low levels of DNA damage were observed at the 24 and 72 h time points. Furthermore, the comet assay revealed gender variability in the levels of DNA damage after short-term exposure.
authors.affiliation: Laboratório de Biologia Molecular, NUPEM/UFRJ, Universidade Federal do Rio de Janeiro, Macae, Brazil, liweberc@gmail.com.
authors.forename: Laura
authors.initials: L
authors.lastname: Weber
authors.forename: Ligia
authors.initials: L
authors.lastname: Carvalho
authors.forename: Natália
authors.initials: N
authors.lastname: Sá
authors.forename: Viviane
authors.initials: V
authors.lastname: Silva
authors.forename: Nathalia
authors.initials: N
authors.lastname: Beraldini
authors.forename: Valderes
authors.initials: V
authors.lastname: Souza
authors.forename: Moisés
authors.initials: M
authors.lastname: Conceição
mesh_terms: D033304:Amphipoda / Q000187:drug effects*; D000818:Animals; D001681:Biological Assay; D001938:Brazil; D055598:Chemical Phenomena; D020552:Comet Assay; D004249:DNA Damage / Q000187:drug effects*; D004784:Environmental Monitoring / Q000379:methods*; D005260:Female; D005618:Fresh Water / Q000737:chemistry*; D006434:Hemocytes / Q000187:drug effects; D007928:Lethal Dose 50; D008297:Male; D010578:Petroleum / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D010578:Petroleum; D014874:Water Pollutants, Chemical