PCB1254暴露致幼年斑马鱼视动反应异常及感光细胞发育相关基因表达变化

摘要

Objective:To study the optomotor response( OMR) and retinal photoreceptor cell growth-related gene expressions of zebrafish larvae after exposed to polychlorinated biphenyls ( PCBs ) after fertilization. Methods:Zebrafish were exposed to PCB1254 at concentrations of 0. 125, 0. 25, 0. 5 and 1 mg · L-1 . A blank group and 0. 01% methanol group were set up. After exposed for 7 d, the visual behavior of zebrafish was assessed using OMR tests. The photoreceptor cell growth-related gene ( CRX, RHO, SWS1 and SWS2 ) expressions were also detected. Results:(1) when the grating spatial frequency was 0. 20 LP·mm-1 and the moving speed was 25 cm· s-1, the OMR sensitive ratio decreased significantly in 0. 5 mg·L-1 and 1 mg·L-1 groups(P<0. 05). (2) The SWS2 gene expressions declined significantly in all the experimental groups ( P <0. 05 ) . The CRX, RHO and SWS1 gene expressions all decreased significantly in 0. 5 mg · L-1 and 1 mg · L-1 groups ( P < 0. 05 ) . Conclusion:Exposed to 0. 5 mg · L-1 and 1 mg · L-1 concentrations of PCB1254 can cause abnormal OMR and down-regulations of the photoreceptor cells growth-related gene expressions, indicating that it is necessary to strengthen the monitoring and control of adverse influences of environmental toxin on the children eyes development.%目的：：研究受精后暴露PCB1254对斑马鱼幼鱼视动反应及视网膜感光细胞发育相关基因表达的影响。方法：对受精后斑马鱼胚胎进行不同质量浓度的PCB1254(0．125、0．25、0．5、1 mg·L-1)暴露处理,同时设立空白对照和0.01%甲醇对照组。暴露7 d后,观察幼年期斑马鱼视动反应及感光细胞发育相关基因CRX、RHO、SWS1、SWS2表达的变化。结果：(1)当条栅空间频率为0．20线· mm-1,移动速度为25 cm · s-1时,0．5 mg·L-1和1 mg·L-1组的幼鱼视动反应敏感比例明显降低(P<0．05)。(2)各实验浓度组的SWS2基因表达均明显下调( P <0．05),0．5 mg · L-1和1 mg · L-1组的 CRX、RHO、SWS1基因表达均明显下调(P<0．05)。结论：0．5 mg·L-1和1 mg·L-1多氯联苯导致幼年期斑马鱼视动反应行为异常及感光细胞发育相关基因表达变化,提示须加强监测和控制环境毒物对儿童眼发育带来的不利影响。