title: Progression of DNA damage induced by a glyphosate-based herbicide in fish (Anguilla anguilla) upon exposure and post-exposure periods--insights into the mechanisms of genotoxicity and DNA repair.
abstract: Roundup® is a glyphosate-based herbicide widely used with both agricultural and non-agricultural purposes, which has been demonstrated to represent a risk to non-target aquatic organisms, namely fish. Among the described effects to fish, genotoxicity has been pointed out as one of the most hazardous. However, the genotoxic mechanisms of Roundup® as well as the involvement of the oxidative DNA damage repair system are not entirely understood. Hence, this work aimed to improve the knowledge on the progression of DNA damage upon short-term exposure (3 days) and post-exposure (1-14 days) periods in association with DNA repair processes in Anguilla anguilla exposed to Roundup® (58 and 116 μg L⁻¹). DNA damage in hepatic cells was evaluated by the comet assay improved with the DNA-lesion specific endonucleases FPG and EndoIII. In order to evaluate the oxidative DNA damage repair ability, an in vitro base excision repair (BER) assay was performed, testing hepatic subcellular extracts. Besides the confirmation of the genotoxic potential of this herbicide, oxidative damage was implicit as an important mechanism of genetic damage, which showed to be transient, since DNA integrity returned to the control levels on the first day after cessation of exposure. An increased capacity to repair oxidative DNA damage emerging in the post-exposure period revealed to be a crucial pathway for the A. anguilla recovery; nevertheless, DNA repair machinery showed to be susceptible to inhibitory actions during the exposure period, disclosing another facet of the risk associated with the tested agrochemical.
authors.affiliation: Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro, Portugal. Electronic address: anammarques@ua.pt.
authors.forename: Ana
authors.initials: A
authors.lastname: Marques
authors.affiliation: Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: Sofia
authors.initials: S
authors.lastname: Guilherme
authors.affiliation: CECAV and Department of Genetics and Biotechnology, Trás-os-Montes and Alto Douro University, 5001-801 Vila Real, Portugal.
authors.forename: Isabel
authors.initials: I
authors.lastname: Gaivão
authors.affiliation: Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: Maria Ana
authors.initials: MA
authors.lastname: Santos
authors.affiliation: Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: Mário
authors.initials: M
authors.lastname: Pacheco
mesh_terms: D000465:Algorithms; D000811:Anguilla; D000818:Animals; D017756:Aquaculture; D001267:Atlantic Ocean; D020552:Comet Assay; D004249:DNA Damage; D004260:DNA Repair / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004781:Environmental Exposure / Q000009:adverse effects; D005998:Glycine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000737:chemistry / Q000633:toxicity; D006540:Herbicides / Q000008:administration & dosage / Q000737:chemistry / Q000633:toxicity; D007700:Kinetics; D008099:Liver / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D009153:Mutagens / Q000008:administration & dosage / Q000737:chemistry / Q000633:toxicity*; D010084:Oxidation-Reduction; D010573:Pesticide Residues / Q000737:chemistry / Q000633:toxicity; D011174:Portugal; D036401:Toxicity Tests, Chronic; D014874:Water Pollutants, Chemical / Q000008:administration & dosage / Q000737:chemistry / Q000633:toxicity*; D000097797:Glyphosate
chemical_list: D005998:Glycine; D006540:Herbicides; D009153:Mutagens; D010573:Pesticide Residues; D014874:Water Pollutants, Chemical; D000097797:Glyphosate
keywords: Base excision repair; DNA damage recovery; Genotoxicity; Oxidative DNA damage repair; Roundup®