Aroclor1254对斑马鱼胚胎发育、肝脏组织结构及其卵黄蛋白原基因的影响

[目的]使用脊椎动物模型斑马鱼评价Aroclor1254对斑马鱼胚胎发育、肝脏组织结构以及卵黄蛋白原（vtg）基因表达的影响，为Aroclor1254的毒性效应研究提供基础数据，以期选择Aroclor1254污染的敏感指标，进行早期污染监测和预警。[方法]将斑马鱼及其胚胎暴露在不同浓度的Aroclor1254溶液中，运用斑马鱼胚胎发育技术和组织病理观察法以及实时定量反转录聚合酶链反应（RT-PCR）检测Aroclor1254对斑马鱼胚胎发育的影响、形态学的改变和卵黄蛋白原（vtg）基因的表达。[结果]斑马鱼胚胎试验显示，3．3、6．5、10．0mg／L Aroclor1254等均可诱导肝变性、肝脏发育不全，其中3.3mg／L Aroclor1254诱导斑马鱼卵黄部分变性，6．5、10．0mg／L Aroclor1254诱导斑马鱼卵黄大部分或者全部变性。肝脏组织病理观察发现，2．0、10．0、50．0μg/L Aroclor1254肝细胞肿大，胞质疏松，空泡明显增加，细胞质中可见脂沉积。vtgmRNA的表达在Aroelor1254暴露的斑马鱼个体中产生了显著的改变，雌鱼中表达普遍呈抑制趋势，其中以2．0μg／L抑制现象最明显，而在雄鱼中该剂量组vtg表达量被显著诱导。[结论]研究表明Aroclor1254对斑马鱼及其胚胎具有毒性效应，肝脏是产生毒性效应的重要靶器官。

Effects of Aroclor1254 on Embryo Development, Histology and Vitellogenin Expression in Liver of Zebrafish

To evaluating the effect of Aroclor1254 on embryo development, histology and vitellogenin gene expression in zebrafish liver so as to provide basiedata of toxic effects of Aroelor1254 and to select sensitive markers for early detection and warning using zebrafish. [ Methods ] Zebrafish and its embryos were exposed to different doses of Aroclor1254. Embryo development technique, histological examination and real-time quantitative polymerase chain reaction （RT-PCR） were used to detect the effect of embryonic development, morphological changes and vitellogenin （vtg） gene expression. [ Results ] The zebrafish embryos test showed that Aroelor1254 induced liver degeneration and hypoplasia at the doses of 3.3, 6.5, 10.0 mg/L. The embryo exhibited part of yolk sac degeneration at 3.3 mg/L, but most degeneration at 6.5, 10.0 mg/L. The histological examination showed that the morphological changes such as cell swelling, cytoplasm loose, vacuoles increase and lipid deposition were observed in liver at doses of 2.0, 10.0, 50 μg/L. The result of real-time quantitative RT-PCR revealed that a significant down-regulation of mRNA vtg gene expression in female zebrafish as compared to the control group, especially at dose of 2.0 μg/L. However, the mRNA vtg gene expression in the male zebrafish was significantly higher than that in the control group at dose of 2.0μg/L. [ Conclusion ] Aroclor1254 has toxic effects on zebrafish and its embryo. Liver could be one of the most important toxic target organs.