title: Upregulation of biotransformation genes in gills of oyster Crassostrea brasiliana exposed in situ to urban effluents, Florianópolis Bay, Southern Brazil.
abstract: The release of untreated sanitary sewage, combined with unplanned urban growth, are major factors contributing to degradation of coastal ecosystems in developing countries, including Brazil. Sanitary sewage is a complex mixture of chemicals that can negatively affect aquatic organisms. The use of molecular biomarkers can help to understand and to monitor the biological effects elicited by contaminants. The aim of this study was to evaluate changes in transcript levels of genes related to xenobiotic biotransformation in the gills of oysters Crassostrea brasiliana transplanted and kept for 24h at three areas potentially contaminated by sanitary sewage (Bücheller river, BUC; Biguaçu river, BIG; and Ratones island, RAT), one farming area (Sambaqui beach, SAM) and at one reference site (Forte beach, FOR) in the North Bay of Santa Catarina Island (Florianópolis, Brazil). Transcript levels of four cytochrome P450 isoforms (CYP2AU1, CYP3A-like, CYP356A1-like and CYP20A1-like), three glutathione S-transferase (GST alpha-like, GST pi-like and GST microsomal 3-like) and one sulfotransferase gene (SULT-like) were evaluated by means of quantitative reverse transcription PCR (qRT-PCR). Chemical analysis of the sediment from each site were performed and revealed the presence of aliphatic and polycyclic aromatic hydrocarbons, linear alkylbenzenes and fecal sterols in the contaminated areas (BUC and BIG). Water quality analysis showed that these sites had the highest levels of fecal coliforms and other parameters evidencing the presence of urban sewage discharges. Among the results for gene transcription, CYP2AU1 and SULT-like levels were upregulated by 20 and 50-fold, respectively, in the oysters kept for 24h at the most contaminated site (BUC), suggesting a role of these genes in the detoxification of organic pollutants. These data reinforce that gills possibly have an important role in xenobiotic metabolism and highlight the use of C. brasiliana as a sentinel for monitoring environmental contamination in coastal regions.
authors.affiliation: Laboratory of Biomarkers of Aquatic Contamination and Immunochemistry - LABCAI, Federal University Santa Catarina, Florianópolis, Brazil.
authors.forename: Tomás B
authors.initials: TB
authors.lastname: Pessatti
authors.affiliation: Laboratory of Biochemistry and Molecular Biology - LBBM, Fishery Engineering Department, Santa Catarina State University, Laguna, Brazil.
authors.forename: Karim H
authors.initials: KH
authors.lastname: Lüchmann
authors.affiliation: Laboratory of Biomarkers of Aquatic Contamination and Immunochemistry - LABCAI, Federal University Santa Catarina, Florianópolis, Brazil.
authors.forename: Fabrício
authors.initials: F
authors.lastname: Flores-Nunes
authors.affiliation: Aquaculture Pathology Research Center - NEPAQ, Federal University of Santa Catarina, Florianópolis, Brazil.
authors.forename: Jacó J
authors.initials: JJ
authors.lastname: Mattos
authors.affiliation: Laboratory of Marine Organic Chemistry, Oceanographic Institute, University of São Paulo, São Paulo 05508-120, Brazil.
authors.forename: Sílvio T
authors.initials: ST
authors.lastname: Sasaki
authors.affiliation: Laboratory of Marine Organic Chemistry, Oceanographic Institute, University of São Paulo, São Paulo 05508-120, Brazil.
authors.forename: Satie
authors.initials: S
authors.lastname: Taniguchi
authors.affiliation: Laboratory of Marine Organic Chemistry, Oceanographic Institute, University of São Paulo, São Paulo 05508-120, Brazil.
authors.forename: Márcia C
authors.initials: MC
authors.lastname: Bícego
authors.affiliation: Laboratory of Biomarkers of Aquatic Contamination and Immunochemistry - LABCAI, Federal University Santa Catarina, Florianópolis, Brazil. Electronic address: afonso.bainy@ufsc.br.
authors.forename: Afonso Celso
authors.initials: AC
authors.lastname: Dias Bainy
mesh_terms: D000818:Animals; D061006:Bays; D001711:Biotransformation / Q000187:drug effects; D001938:Brazil; D049896:Crassostrea / Q000187:drug effects*; D003577:Cytochrome P-450 Enzyme System / Q000187:drug effects / Q000235:genetics; D004784:Environmental Monitoring / Q000379:methods; D005880:Gills / Q000187:drug effects*; D005982:Glutathione Transferase / Q000378:metabolism; D007527:Isoenzymes / Q000378:metabolism; D012499:Sanitation; D012722:Sewage / Q000737:chemistry; D014158:Transcription, Genetic / Q000187:drug effects; D015854:Up-Regulation; D062065:Wastewater / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity*; D015262:Xenobiotics / Q000378:metabolism
chemical_list: D003577:Cytochrome P-450 Enzyme System; D005982:Glutathione Transferase; D007527:Isoenzymes; D012722:Sewage; D062065:Wastewater; D014874:Water Pollutants, Chemical; D015262:Xenobiotics; C119995:glutathione S-transferase alpha
keywords: Biomarker; Crassostrea brasiliana; Cytochrome P450; Glutathione S-transferase; Sanitary sewage; Sulfotransferase