title: Evaluation of biomarker potential of cytochrome P450 1A (CYP1A) gene in the marine medaka, Oryzias melastigma exposed to water-accommodated fractions (WAFs) of Iranian crude oil.
abstract: CYP1A is involved in the metabolism of diverse chemicals, including polycyclic aromatic hydrocarbons and alkylated-PAHs, as a first line of detoxification mechanism. First, we identified and characterized the CYP1A gene from the marine medaka, Oryzias melastigma. O. melastigma CYP1A (Om-CYP1A) showed a high similarity of motifs/domains compared to those of vertebrates in their amino acid sequences. To check whether the Om-CYP1A would be inducible, we tested two strong CYP1A inducers, β-naphthoflavone (β-NF) and benzo[α]pyrene (B[α]P), and observed concentration-dependent transient expression on transcripts of Om-CYP1A for 96 h over a wide range of concentrations. Om-CYP1A mRNA level was significantly increased in exposure to different concentrations of β-NF and B[α]P, and its expression was highly transcribed within 12 h upon the exposure to low concentrations of both chemicals. Inducible transcript profiles revealed that Om-CYP1A would be associated with the toxicant metabolism via AhREs/DREs/XREs in its promoter region. To uncover the effects of the water-accommodated fraction (WAF) of crude oil on transcripts of Om-CYP1A, we measured mRNA expression of Om-CYP1A towards different concentrations of WAF for 24h. As a result, WAF exposure significantly increased Om-CYP1A transcripts at all concentrations as well as during time-course experiments for 96 h. In this paper, we demonstrated that WAF would trigger up-regulation of the CYP1A gene that would be associated with the initiation of the cellular defense systems. This finding provides a better understanding of the molecular mechanism of cellular protection particularly that involved in the WAF-mediated cellular response in O. melastigma.
authors.affiliation: Department of Chemistry, College of Natural Sciences, Hanyang University, Seoul 133-791, South Korea.
authors.forename: Ryeo-Ok
authors.initials: RO
authors.lastname: Kim
authors.forename: Bo-Mi
authors.initials: BM
authors.lastname: Kim
authors.forename: Dae-Sik
authors.initials: DS
authors.lastname: Hwang
authors.forename: Doris W T
authors.initials: DW
authors.lastname: Au
authors.forename: Jee-Hyun
authors.initials: JH
authors.lastname: Jung
authors.forename: Won Joon
authors.initials: WJ
authors.lastname: Shim
authors.forename: Kenneth M Y
authors.initials: KM
authors.lastname: Leung
authors.forename: Rudolf S S
authors.initials: RS
authors.lastname: Wu
authors.forename: Jae-Sung
authors.initials: JS
authors.lastname: Rhee
authors.forename: Jae-Seong
authors.initials: JS
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001564:Benzo(a)pyrene / Q000378:metabolism / Q000633:toxicity; D015415:Biomarkers / Q000378:metabolism; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D029941:Fish Proteins / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D050216:Metabolic Detoxication, Phase I; D008969:Molecular Sequence Data; D009990:Oryzias / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D010578:Petroleum; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity*; D019324:beta-Naphthoflavone / Q000378:metabolism / Q000633:toxicity
chemical_list: D015415:Biomarkers; D029941:Fish Proteins; D010578:Petroleum; D014874:Water Pollutants, Chemical; D001564:Benzo(a)pyrene; D019324:beta-Naphthoflavone; D019363:Cytochrome P-450 CYP1A1