title: Genetic and biochemical effects induced by iron ore, Fe and Mn exposure in tadpoles of the bullfrog Lithobates catesbeianus.
abstract: For decades, the extraction of minerals has intensified in order to meet the demand of industry. Iron ore deposits are important sources of metals, such as iron (Fe) and manganese (Mn). The particulate ores can be dispersed during extraction, transport and storage, with potential to induce biological impacts. Amphibians are very sensitive to environmental stressors. Therefore, the present study aimed to assess the effects of iron ore, Fe and Mn exposure during the metamorphosis of Lithobates catesbeianus. Endpoints analyzed included morphological (biometrical and developmental analyses), whole body Fe and Mn concentration in, plasma ferritin concentration, erythrocyte DNA damage (measured through comet assay and micronucleus test) and liver activity of enzymes involved in oxidative status [glutathione S-transferase (GST) and catalase (CAT)]. Tadpoles were kept under control condition (no contaminant addition) or exposed to iron ore (3.79mg/L as fine particulate matter); Fe (nominal concentration: 0.51mg/L Fe as C10H12FeN2NaO8; Fe-EDTA); and Mn (nominal concentration: 5.23mg/L Mn as 4H2O.MnCl2) for 30 days. Virtually, no mortality was observed, except for one tadpole found dead in the iron ore treatment. However, tadpoles exposed to iron ore had longer tail than those kept under control conditions while tadpoles exposed to manganese chloride showed higher body length than control ones. Exposure to Fe and Mn induced a delay in tadpole metamorphosis, especially when these metals are presented not as a mixture (iron ore). Tadpoles exposed to iron ore had increased whole body Fe and Mn while those exposed to Fe and Mn accumulated each metal individually. Tadpoles exposed to any of the contaminants tested showed a significant increase in erythrocyte DNA damage and frequency of micronuclei. In addition, they showed higher liver GST activity respect with those kept under control conditions. Plasma ferritin concentration and liver CAT activity were higher only in tadpoles exposed to iron ore. These findings indicated that tadpoles accumulated Fe and Mn at the whole body level after exposure to the single metals or to their mixture as iron ore. In addition, they indicate that Fe and Mn accumulation can induce oxidative stress with consequent significant developmental, genotoxic and biochemical effects in L. catesbeianus tadpoles.
authors.affiliation: Universidade Vila Velha-UVV, Laboratório de Ictiologia Aplicada (LAB PEIXE), Rua Comissário José Dantas de Melo no 21, Boa Vista, 29102-770 Vila Velha, ES, Brazil. Electronic address: alexandra_veronez@hotmail.com.
authors.forename: Alexandra Caroline da Silva
authors.initials: AC
authors.lastname: Veronez
authors.affiliation: Universidade Vila Velha-UVV, Laboratório de Ictiologia Aplicada (LAB PEIXE), Rua Comissário José Dantas de Melo no 21, Boa Vista, 29102-770 Vila Velha, ES, Brazil. Electronic address: rvsalla@gmail.com.
authors.forename: Rômulo Victor
authors.initials: RV
authors.lastname: Salla
authors.affiliation: Universidade Vila Velha-UVV, Laboratório de Ictiologia Aplicada (LAB PEIXE), Rua Comissário José Dantas de Melo no 21, Boa Vista, 29102-770 Vila Velha, ES, Brazil. Electronic address: vinicius.baroni@hotmail.com.
authors.forename: Vinícius Dadalto
authors.initials: VD
authors.lastname: Baroni
authors.affiliation: Universidade do Estado de Santa Catarina-UDESC, Av. Madre Benvenuta, 2007-Itacorubi, 88035-001 Florianópolis, SC, Brazil. Electronic address: barcarolli@gmail.com.
authors.forename: Indianara Fernanda
authors.initials: IF
authors.lastname: Barcarolli
authors.affiliation: Universidade Federal do Rio Grande-FURG, Instituto de Ciências Biológicas, Av. Itália km 8, Carreiros, 96, 203-900 Rio Grande, RS, Brazil. Electronic address: adaltobianchini@furg.br.
authors.forename: Adalto
authors.initials: A
authors.lastname: Bianchini
authors.affiliation: Universidade Estadual de Londrina - UEL, Departamento de Ciências Fisiológicas, Laboratório de Ecofisiologia Animal, Caixa-postal: 10011, 86057-970 Londrina, PR, Brazil. Electronic address: claudiabmartinez@gmail.com.
authors.forename: Claudia Bueno
authors.initials: CB
authors.lastname: Dos Reis Martinez
authors.affiliation: Universidade Vila Velha-UVV, Laboratório de Ictiologia Aplicada (LAB PEIXE), Rua Comissário José Dantas de Melo no 21, Boa Vista, 29102-770 Vila Velha, ES, Brazil. Electronic address: adriana.chippari@uvv.br.
authors.forename: Adriana Regina
authors.initials: AR
authors.lastname: Chippari-Gomes
mesh_terms: D000818:Animals; D002374:Catalase / Q000378:metabolism; D004247:DNA / Q000187:drug effects*; D004249:DNA Damage / Q000187:drug effects; D004781:Environmental Exposure; D004912:Erythrocytes / Q000187:drug effects; D005293:Ferritins / Q000097:blood; D005982:Glutathione Transferase / Q000378:metabolism; D007501:Iron / Q000633:toxicity*; D007814:Larva / Q000187:drug effects; D008099:Liver / Q000187:drug effects* / Q000201:enzymology; D008345:Manganese / Q000633:toxicity*; D008675:Metamorphosis, Biological / Q000187:drug effects; D015162:Micronucleus Tests; D011892:Rana catesbeiana / Q000235:genetics / Q000502:physiology*; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D014874:Water Pollutants, Chemical; D008345:Manganese; D004247:DNA; D005293:Ferritins; D007501:Iron; D002374:Catalase; D005982:Glutathione Transferase
keywords: Amphibians; Biochemical effects; DNA damage; Metal bioaccumulation; Metamorphosis