Detecting Exposure to Surface Water Contaminants Non-lethally Using Atlantic Salmon ( Salmo salar ) Scales

• Main Author: Skall, Daniel Gerhard
• Format: Text
• Language: unknown
• Published: DigitalCommons@UMaine 2011
• Subjects: Water pollution; Runoff; Maine; Water quality; Endangered species; Rare fishes; Aquaculture and Fisheries; Fresh Water Studies; Natural Resources and Conservation; Terrestrial and Aquatic Ecology; Atlantic salmon; Salmo salar
• Online Access: https://digitalcommons.library.umaine.edu/etd/1246; https://digitalcommons.library.umaine.edu/context/etd/article/2283/viewcontent/SkallD2011.pdf

There is great need for non-lethal, biologically relevant screening tools to assess the effects of surface water contaminants on threatened or endangered fish species, as typical screening procedures, such as liver sampling and skin plugs, are lethal or highly invasive. Evidence suggests that fish scales biochemically respond to a range of contaminants and, therefore, could serve as non-lethal, rapid biosensors of fish exposure to contaminants. Cytochrome P4501A (CYP1A) is a monooxygenase biomarker commonly measured in organisms to determine exposure to organic contaminants, and evidence suggests that CYP1A is expressed in bone cells (and fish scales). Vitellogenin β (VtgB) is a glycoprotein biomarker commonly measured in organisms to determine exposure to estrogenic contaminants, and evidence suggests that VtgB is expressed in fish scales. We were interested in determining the location of CYP1A protein in and around the fish scales. We were also interested in establishing if scale CYP1A and VtgB would respond to contaminant exposures. We aqueously exposed Atlantic salmon (Salmo salar) parr for 48-hours to 40 ppb acetone, left them untreated, or exposed them to 0.327, 3.27, or 32.7 ppb 3,4,3',4',5-pentachlorobiphenyl (PCB126), to 0.01, 0.1, or 34 ppb fluoxetine hydrochloride (FLU), to 27.2 or 330 ppb β-naphthoflavone (BNF) to assess responses to organic contaminants. We also aqueously exposed S. salar parr for 96-hours to 40 ppb ethanol-treated or untreated controls or to 10,000 ppb 17α-ethinylestradiol (EE2) to assess responses to an estrogenic contaminant. Regarding CYP1A protein location, we hypothesized that the CYP1A protein is expressed in scale osteoblasts (bone-forming cells). Regarding scale biomarker response to contaminant exposure, we hypothesized that 1) fish scale CYP1A mRNA would be induced by PCB126, BNF, and FLU, and 2) fish scale VtgB mRNA would be induced by EE2. Through immunohistochemical analysis of skin-scale sections using CYP1A-specific MAb 1-12-3, we observed CYP1A protein location in ...