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【目的】探讨环境有机污染物多氯联苯暴露对斑马鱼视网膜形态学及视锥-视杆同源盒基因(cone-rod ho-meobox,CRX)表达的影响。【方法】以斑马鱼为模式生物,配制1.0、0.5、0.25、0.125 mg/L 4个不同浓度的多氯联苯对斑马鱼胚胎进行暴露处理,同时设空白对照和0.01%甲醇对照组,观察多氯联苯暴露对斑马鱼幼鱼存活率、视网膜形态学及CRX基因表达变化情况。【结果】1)低浓度(0.125 mg/L)多氯联苯暴露对斑马鱼幼鱼的存活率、视网膜形态学、CRX基因表达均无明显影响;2)中、高浓度(0.25 mg/L以上)的多氯联苯暴露96 hpf后,斑马鱼存活率明显下降;视网膜总厚度、神经节细胞层、感光细胞层厚度均较对照组明显增厚(P<0.05),感光细胞层细胞排列紊乱,同时在1 mg/L多氯联苯暴露组中可见感光细胞数明显减少;中、高浓度的多氯联苯暴露组CRX基因表达均较对照组明显降低(P<0.05)。【结论】中、高浓度的多氯联苯暴露对斑马鱼视网膜尤其是感光细胞层产生明显的毒害作用,必须加强对环境有机污染物的监测和控制。
【Objective】 The purpose of this study was to investigate the effects of exposure to PCBs on the retinal morphology and the expression of cone-rod ho-meobox (CRX) in zebrafish. 【Method】 The zebrafish embryos were exposed to 4 different concentrations of PCBs (1.0, 0.5, 0.25 and 0.125 mg / L) with zebrafish as model organism. At the same time, blank control and 0.01% Survival of PCBs, retinal morphology and CRX gene expression in PCBs exposed to PCBs. 【Result】 1) Exposure of PCBs at low concentration (0.125 mg / L) did not affect the survival, retinal morphology and CRX gene expression of zebrafish larvae. 2) Medium and high concentrations of 0.25 mg / L ) Exposed to 96 hpf of PCBs, the survival rate of zebrafish decreased significantly. The total retinal thickness, ganglion cell layer and photoreceptor cell layer thickness were significantly thicker than the control group (P <0.05) At the same time, the number of photoreceptor cells in 1 mg / L PCB exposure group was obviously decreased. The CRX gene expression in PCB exposure group was significantly lower than that in control group (P <0.05). 【Conclusion】 The medium and high concentrations of PCB exposure have obvious toxic effects on zebrafish retina, especially photoreceptor cell layer, and the monitoring and control of environmental organic pollutants must be strengthened.