title: Histological responses and localization of the cytochrome P450 (CYP2AU1) in Crassostrea brasiliana exposed to phenanthrene.
abstract: Phenanthrene (PHE) is an abundant polycyclic aromatic hydrocarbon (PAH), widely distributed in aquatic environment. The aim of this study was to evaluate the histological and molecular effects in the native oyster Crassostrea brasiliana(Lamarck, 1819) exposed to 100 and 1000 μg L(-1) PHE for 1, 5 and 10 days. Histological and chemical analyses were performed to evaluate, respectively, alterations in oyster tissues and bioaccumulation. In situ hybridization (ISH) was used to assess tissue distribution of CYP2AU1, a gene formerly identified as activated by PHE exposure in this species.Quantitative polymerase chain reaction (qPCR) in mantle was carried out to validate ISH data. Oysters bioaccumulated PHE increasingly along the exposure period in both exposure concentrations. Histologic changes, like tubular atrophy in digestive diverticula (digestive gland) and increased number of mucous cells in the mantle were observed in animals exposed to PHE for 10 days. ISH showed the presence of CYP2AU1transcripts in gills, digestive diverticula, mantle, intestine and gonads, but significant differences in transcript detection by ISH between treatments occurred only in gills, mantle and intestine. A positive and significant correlation between tubular atrophy and CYP2AU1hybridization signal was observed in digestive diverticula, suggesting that this gene product might be involved in energetic metabolism in C. brasiliana. Increased mucous cells and CYP2AU1transcript levels were observed in the mantle, where the inner and middle lobes showed higher intensity of hybridization signal. Mantle should be considered as a target organ for CYP2AU1 transcript evaluation and histological alterations in biomonitoring studies. CYP2AU1 signal in female gonads was observed in all follicular cells from different gonadic stages, while in male only the spermatic follicle cells of the wall in the pre-spawning stage showed this signal. ISH was an effective technique to evaluate the effects of PHE exposure and to locate CYP2AU1 transcripts in different tissues of oyster C. brasiliana.
authors.affiliation: Laboratory of Biomarkers of Aquatic Contamination and Immunochemistry-LABCAI, Federal University of Santa Catarina, UFSC, Florianópolis, Santa Catarina, Brazil.
authors.forename: Isis M M
authors.initials: IM
authors.lastname: dos Reis
authors.affiliation: Laboratory of Biomarkers of Aquatic Contamination and Immunochemistry-LABCAI, Federal University of Santa Catarina, UFSC, Florianópolis, Santa Catarina, Brazil; Aquaculture Pathology Research Center-NEPAQ, Federal University of Santa Catarina, UFSC, Florianópolis, Brazil.
authors.forename: Jacó J
authors.initials: JJ
authors.lastname: Mattos
authors.affiliation: Laboratory of Stem Cells and Tissue Regeneration, Federal University of Santa Catarina, UFSC, Florianópolis, Santa Catarina, Brazil.
authors.forename: Ricardo C
authors.initials: RC
authors.lastname: Garcez
authors.affiliation: Laboratory of Biomarkers of Aquatic Contamination and Immunochemistry-LABCAI, Federal University of Santa Catarina, UFSC, Florianópolis, Santa Catarina, Brazil.
authors.forename: Flávia L
authors.initials: FL
authors.lastname: Zacchi
authors.affiliation: Laboratory of Biomarkers of Aquatic Contamination and Immunochemistry-LABCAI, Federal University of Santa Catarina, UFSC, Florianópolis, Santa Catarina, Brazil.
authors.forename: Talita
authors.initials: T
authors.lastname: Miguelão
authors.affiliation: Laboratory of Biomarkers of Aquatic Contamination and Immunochemistry-LABCAI, Federal University of Santa Catarina, UFSC, Florianópolis, Santa Catarina, Brazil.
authors.forename: Fabrício
authors.initials: F
authors.lastname: Flores-Nunes
authors.affiliation: Laboratory of Biomarkers of Aquatic Contamination and Immunochemistry-LABCAI, Federal University of Santa Catarina, UFSC, Florianópolis, Santa Catarina, Brazil.
authors.forename: Guilherme
authors.initials: G
authors.lastname: Toledo-Silva
authors.affiliation: Laboratory of Marine Organic Chemistry-LABQOM, Oceanographic Institute, University of São Paulo, USP, São Paulo, São Paulo, Brazil.
authors.forename: Sílvio T
authors.initials: ST
authors.lastname: Sasaki
authors.affiliation: Laboratory of Marine Organic Chemistry-LABQOM, Oceanographic Institute, University of São Paulo, USP, São Paulo, São Paulo, Brazil.
authors.forename: Satie
authors.initials: S
authors.lastname: Taniguchi
authors.affiliation: Laboratory of Marine Organic Chemistry-LABQOM, Oceanographic Institute, University of São Paulo, USP, São Paulo, São Paulo, Brazil.
authors.forename: Márcia C
authors.initials: MC
authors.lastname: Bícego
authors.affiliation: Laboratory of Histological Markers, Federal Institute of Education Science and Technology of Santa Catarina, IFSC, Garopaba, Santa Catarina, Brazil.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Cargnin-Ferreira
authors.affiliation: Laboratory of Biomarkers of Aquatic Contamination and Immunochemistry-LABCAI, Federal University of Santa Catarina, UFSC, Florianópolis, Santa Catarina, Brazil. Electronic address: afonso.bainy@ufsc.br.
authors.forename: Afonso C D
authors.initials: AC
authors.lastname: Bainy
mesh_terms: D000818:Animals; D049896:Crassostrea / Q000187:drug effects* / Q000201:enzymology; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D004784:Environmental Monitoring / Q000379:methods*; D005880:Gills / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D007422:Intestines / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D008297:Male; D010084:Oxidation-Reduction; D010616:Phenanthrenes / Q000633:toxicity*; D013270:Stomach / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D010616:Phenanthrenes; D014874:Water Pollutants, Chemical; C031181:phenanthrene; D003577:Cytochrome P-450 Enzyme System
keywords: Biomarker; Cytochrome P450; Histopathology; ISH; Oyster; PAH