Department of Biomedical Sciences, Chonnam National University Medical School, Gwangju, Republic of Korea.
Aquat Toxicol. 2013 Jun 15;134-135:57-65. doi: 10.1016/j.aquatox.2013.03.010. Epub 2013 Mar 21.
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.
2,3,7,8-四氯二苯并对二恶英（TCDD）是各种工业过程的意外副产品，被归类为人类致癌物，可能会破坏生殖、发育和内分泌系统。细胞色素 P4501A1（CYP1A1）的诱导被用作 TCDD 暴露的指标。我们试图使用转基因斑马鱼（Danio rerio）模型确定易受 TCDD 毒性影响的组织。我们使用 DNA 重组技术将一个核增强型绿色荧光蛋白基因（EGFP）插入到一个fosmid 克隆中的斑马鱼 CYP1A 基因的起始密码子中。然后，用重组的 fosmid 产生 CYP1A 报告斑马鱼，将其胚胎暴露于 TCDD 中。报告斑马鱼中 EGFP 的表达模式与内源性 CYP1A mRNA 的表达模式相吻合。此外，胚胎在低至 10 pM 的 TCDD 暴露 72 小时，不会引起胚胎形态异常，明显增加 GFP 表达。此外，报告胚胎也对其他 AhR 配体有反应。胚胎暴露于 TCDD 中揭示了先前报道的（心血管系统、肝脏、胰腺、肾脏、鳔和皮肤）和未报道的靶组织（视网膜双极细胞、耳囊、侧线、泄殖腔和胸鳍芽）对 TCDD 的反应。我们开发的转基因 CYP1A 报告斑马鱼可以进一步了解 TCDD 的生态毒理学相关性和人类健康风险。此外，它们可用于鉴定 AhR 的激动剂和 TCDD 毒性的解毒剂。
