title: Molecular responses of Walleye (Sander vitreus) embryos to naphthenic acid fraction components extracted from fresh oil sands process-affected water.
abstract: Naphthenic acid fraction components (NAFCs) are constituents of oil sands process-affected water (OSPW), which is generated as a result of unconventional oil production via surface mining in the Athabasca oil sands region. NAFCs are often considered to be major drivers of OSPW toxicity to various taxa, including fishes. However, the molecular targets of these complex mixtures are not fully elucidated. Here we examined the effects in walleye (Sander vitreus) embryos after exposure to NAFCs extracted from fresh OSPW. Eleutheroembryos (exposed to 0, 4.2 or 8.3mg/L NAFCs from 1day post-fertilization to hatch) were subsampled, measured for growth and deformities, and molecular responses were assessed via real-time polymerase chain reaction (PCR). Fourteen genes were evaluated, with a focus on the aryl-hydrocarbon receptor (AhR) - cytochrome P450 pathway (arnt, cyp1a1), the oxidative stress axis (cat, gst, sod, gpx1b), apoptosis (e.g. casp3, bax and p53), growth factor signaling (e.g. insulin-like growth factors igf1, igf1b, and igf1bp), and tissue differentiation (vim). NAFC exposure was associated with an increase in the expression of cyp1a1, and a decrease in gpx1b and ribosomal protein rps40. These results indicate that NAFC effects on walleye early-life stages may be mediated through oxidative stress via pathways that include AhR.
authors.affiliation: Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, ON, Canada.
authors.forename: Julie R
authors.initials: JR
authors.lastname: Marentette
authors.affiliation: Department of Biology, University of New Brunswick, Saint John, Canada.
authors.forename: Kathleena
authors.initials: K
authors.lastname: Sarty
authors.affiliation: Department of Biology, University of New Brunswick, Saint John, Canada.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Cowie
authors.affiliation: Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, ON, Canada.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Frank
authors.affiliation: Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, ON, Canada.
authors.forename: L Mark
authors.initials: LM
authors.lastname: Hewitt
authors.affiliation: Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, ON, Canada.
authors.forename: Joanne L
authors.initials: JL
authors.lastname: Parrott
authors.affiliation: Department of Biology, University of New Brunswick, Saint John, Canada.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Martyniuk
mesh_terms: D000818:Animals; D002264:Carboxylic Acids / Q000737:chemistry / Q000633:toxicity*; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics; D004625:Embryo, Nonmammalian / Q000187:drug effects*; D029941:Fish Proteins / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects*; D061329:Oil and Gas Fields / Q000737:chemistry*; D018384:Oxidative Stress / Q000187:drug effects / Q000235:genetics; D010088:Oxidoreductases / Q000235:genetics; D010471:Perches / Q000502:physiology*; D060888:Real-Time Polymerase Chain Reaction; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D002264:Carboxylic Acids; D029941:Fish Proteins; D014874:Water Pollutants, Chemical; D010088:Oxidoreductases; D019363:Cytochrome P-450 CYP1A1; C046170:naphthenic acid
keywords: AEOs; Apoptosis; Deformities; Embryos; NAFCs; OSPW; Oil sands; Oxidative stress; cyp1a