title: Cyp1a reporter zebrafish reveals target tissues for dioxin.
abstract: 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is the unintentional byproduct of various industrial processes, is classified as human carcinogen and could disrupt reproductive, developmental and endocrine systems. Induction of cyp1a1 is used as an indicator of TCDD exposure. We sought to determine tissues that are vulnerable to TCDD toxicity using a transgenic zebrafish (Danio rerio) model. We inserted a nuclear enhanced green fluorescent protein gene (EGFP) into the start codon of a zebrafish cyp1a gene in a fosmid clone using DNA recombineering. The resulting recombineered fosmid was then used to generate cyp1a reporter zebrafish, embryos of which were exposed to TCDD. Expression pattern of EGFP in the reporter zebrafish mirrored that of endogenous cyp1a mRNA. In addition, exposure of the embryos to TCDD at as low as 10 pM for 72 h, which does not elicit morphological abnormalities of embryos, markedly increased GFP expression. Furthermore, the reporter embryos responded to other AhR ligands as well. Exposure of the embryos to TCDD revealed previously reported (the cardiovascular system, liver, pancreas, kidney, swim bladder and skin) and unreported target tissues (retinal bipolar cells, otic vesicle, lateral line, cloaca and pectoral fin bud) for TCDD. Transgenic cyp1a reporter zebrafish we have developed can further understanding of ecotoxicological relevance and human health risks by TCDD. In addition, they could be used to identify agonists of AhR and antidotes to TCDD toxicity.
authors.affiliation: Department of Biomedical Sciences, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Kun-Hee
authors.initials: KH
authors.lastname: Kim
authors.forename: Hye-Jeong
authors.initials: HJ
authors.lastname: Park
authors.forename: Jin Hee
authors.initials: JH
authors.lastname: Kim
authors.forename: Suhyun
authors.initials: S
authors.lastname: Kim
authors.forename: Darren R
authors.initials: DR
authors.lastname: Williams
authors.forename: Myeong-Kyu
authors.initials: MK
authors.lastname: Kim
authors.forename: Young Do
authors.initials: YD
authors.lastname: Jung
authors.forename: Hiroki
authors.initials: H
authors.lastname: Teraoka
authors.forename: Hae-Chul
authors.initials: HC
authors.lastname: Park
authors.forename: Hyon E
authors.initials: HE
authors.lastname: Choy
authors.forename: Boo Ahn
authors.initials: BA
authors.lastname: Shin
authors.forename: Seok-Yong
authors.initials: SY
authors.lastname: Choi
mesh_terms: D058500:Animal Fins / Q000378:metabolism; D000818:Animals; D030801:Animals, Genetically Modified; D015415:Biomarkers / Q000378:metabolism*; D015153:Blotting, Western; D022202:Chromosomes, Artificial, Bacterial / Q000235:genetics; D002988:Cloaca / Q000378:metabolism; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D004785:Environmental Pollutants / Q000378:metabolism* / Q000633:toxicity; D005786:Gene Expression Regulation / Q000187:drug effects*; D005818:Genetic Engineering / Q000379:methods*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D017403:In Situ Hybridization; D053403:Lateral Line System / Q000378:metabolism; D018613:Microscopy, Confocal; D000072317:Polychlorinated Dibenzodioxins / Q000378:metabolism* / Q000633:toxicity; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012160:Retina / Q000378:metabolism; D015027:Zebrafish
chemical_list: D015415:Biomarkers; D017931:DNA Primers; D004785:Environmental Pollutants; D000072317:Polychlorinated Dibenzodioxins; D011994:Recombinant Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D019363:Cytochrome P-450 CYP1A1