title: A non-lethal method to estimate CYP1A expression in laboratory and wild Atlantic salmon (Salmo salar).
abstract: Expression of cytochrome P4501A (CYP1A) has been used as a biomarker for possible exposure to contaminants such as PCBs and dioxins in teleost fish. Using a quantitative reverse transcription-polymerase chain reaction (Q-RT-PCR) and a non-lethal gill biopsy, we estimated levels of CYP1A mRNA expression in Atlantic salmon (Salmo salar). Groups of ten Atlantic salmon juveniles (48-76 g) received an intraperitoneal injection of 50 microg g(-1) beta-naphthoflavone (BNF) or vehicle. Their gill tissues were repeatedly sampled by non-lethal biopsies on day 0, 1, 2 and 7. Control fish expressed basal levels of CYP1A over the duration of sampling. BNF-treated salmon demonstrated similar levels of CYP1A to control fish at day 0 and higher levels over the course of each additional sampling point. Gill biopsies from wild salmon sampled from Millers River (South Royalston, Worcester County, MA, USA), known to contain PCBs, showed significantly higher CYP1A levels over an uncontaminated reference stream, Fourmile Brook (Northfield, Franklin County, MA, USA). We conclude that gill biopsies coupled with Q-RT-PCR analysis is a valuable tool in environmental assessment of wild Atlantic salmon populations and has the potential to be applied to other populations of fish as well.
authors.affiliation: Department of Fisheries and Wildlife, 13 Natural Resources Building, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Rees
authors.forename: Stephen D
authors.initials: SD
authors.lastname: McCormick
authors.forename: Weiming
authors.initials: W
authors.lastname: Li
mesh_terms: D000818:Animals; D000830:Animals, Laboratory; D000835:Animals, Wild; D015415:Biomarkers / Q000378:metabolism; D001706:Biopsy; D019363:Cytochrome P-450 CYP1A1 / Q000096:biosynthesis* / Q000187:drug effects / Q000235:genetics; D004781:Environmental Exposure; D004784:Environmental Monitoring / Q000379:methods*; D004791:Enzyme Inhibitors / Q000633:toxicity; D005618:Fresh Water; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D005880:Gills / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology*; D007274:Injections, Intraperitoneal; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020317:Salmo salar / Q000378:metabolism*; D014873:Water Pollutants / Q000633:toxicity; D019324:beta-Naphthoflavone / Q000633:toxicity
chemical_list: D015415:Biomarkers; D004791:Enzyme Inhibitors; D012333:RNA, Messenger; D014873:Water Pollutants; D019324:beta-Naphthoflavone; D019363:Cytochrome P-450 CYP1A1