title: Time-dependent expression and activity of cytochrome P450 1s in early life-stages of the zebrafish (Danio rerio).
abstract: Zebrafish embryos are being increasingly used as model organisms for the assessment of single substances and complex environmental samples for regulatory purposes. Thus, it is essential to fully understand the xenobiotic metabolism during the different life-stages of early development. The aim of the present study was to determine arylhydrocarbon receptor (AhR)-mediated activity during selected times of early development using qPCR, enzymatic activity through measurement of 7-ethoxyresorufin-O-deethylase (EROD) activity, and protein expression analysis. In the present study, gene expression of cyp1a, cyp1b1, cyp1c1, cyp1c2, and ahr2 as well as EROD activity were investigated up to 120 h postfertilization (hpf) after exposure to either β-naphthoflavone (BNF) or a polycyclic aromatic hydrocarbons (PAH)-contaminated sediment extract from Vering Kanal in Hamburg (VK). Protein expression was measured at 72 hpf after exposure to 20 μg/L BNF. Altered proteins were identified by matrix assisted laser desorption ionization time-of-flight (MALDI-TOF) peptide mass fingerprinting. Distinct patterns of basal messenger RNA (mRNA) expression were found for each of the cyp1 genes, suggesting specific roles during embryonic development. All transcripts were induced by BNF and VK. ahr2 mRNA expression was significantly upregulated after exposure to VK. All cyp1 genes investigated showed a temporal decline in expression at 72 hpf. The significant decline of Hsp 90β protein at 72 hpf after exposure to BNF may suggest an explanation for the decline of cyp1 genes at this time point as Hsp 90β is of major importance for the functioning of the Ah-receptor. EROD activity measured in embryos was significantly induced after 96 hpf of exposure to BNF or VK. Together, these results demonstrate distinct temporal patterns of cyp1 genes and protein activities in zebrafish embryos as well as show a need to investigate further the xenobiotic biotransformation system during early development of zebrafish.
authors.affiliation: Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany. j.braunig@uq.edu.au.|National Research Centre for Environmental Toxicology (Entox), The University of Queensland, 39 Kessels Road, 4108, Brisbane, Queensland, Australia. j.braunig@uq.edu.au.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Bräunig
authors.affiliation: Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Schiwy
authors.affiliation: Molecular Biotechnology and Functional Genomics, Technical University of Applied Sciences Wildau, Hochschulring 1, 15745, Wildau, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Broedel
authors.affiliation: Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Müller
authors.affiliation: Molecular Biotechnology and Functional Genomics, Technical University of Applied Sciences Wildau, Hochschulring 1, 15745, Wildau, Germany.
authors.forename: Marcus
authors.initials: M
authors.lastname: Frohme
authors.affiliation: Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany.
authors.forename: Henner
authors.initials: H
authors.lastname: Hollert
authors.affiliation: Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany. steffen.keiter@oru.se.|Man-Technology-Environment Research Centre, School of Science and Technology, Örebro University, 70182, Örebro, Sweden. steffen.keiter@oru.se.
authors.forename: Steffen H
authors.identifier: http://orcid.org/0000-0002-2356-6686
authors.initials: SH
authors.lastname: Keiter
mesh_terms: D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000187:drug effects / Q000378:metabolism; D047108:Embryonic Development; D015870:Gene Expression / Q000187:drug effects; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D008658:Inactivation, Metabolic; D011084:Polycyclic Aromatic Hydrocarbons / Q000633:toxicity; D018336:Receptors, Aryl Hydrocarbon / Q000235:genetics / Q000378:metabolism; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism; D019324:beta-Naphthoflavone / Q000633:toxicity
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D018336:Receptors, Aryl Hydrocarbon; D029961:Zebrafish Proteins; D019324:beta-Naphthoflavone; D001189:Aryl Hydrocarbon Hydroxylases
keywords: Arylhydrocarbon receptor; Cytochrome P450; EROD; Hsp 90β; Zebrafish; β-naphthoflavone