全氟辛烷磺酸(PFOS)对斑马鱼卵黄蛋白原mRNA水平的影响

Effects of Perfluorooctane Sulfonate(PFOS) Exposure on Vitellogenin mRNA Level in Zebrafish(Brachydanio rerio)

为了研究环境低剂量全氟辛烷磺酸(perfluorooctane sulfonate,PFOS)对水生生物的内分泌干扰效应和可能的作用机制,测定了PFOS对斑马鱼(Brachydanio rerio)肝脏中卵黄蛋白原(vitellogenin,VTG)mRNA水平的影响.将斑马鱼暴露于4个PFOS的环境低剂量浓度组(0.1、1、10、100μg.L-1)中进行21d毒性试验,收集肝脏样品,提取RNA,采用荧光定量PCR(qRT-PCR)分别检测VTG1和VTG3的mRNA水平.结果表明:①PFOS暴露引起雄性斑马鱼肝脏VTG1和VTG3 mRNA水平升高,VTG1 mRNA水平升高与剂量呈正相关,在100μg.L-1暴露浓度处与对照组呈现显著性差异;VTG3的mRNA水平变化与剂量呈倒U型曲线,呈现典型的毒物刺激荷尔蒙效应,在10和100μg.L-1暴露浓度处与对照组呈现显著性差异;②PFOS暴露引起雌性斑马鱼肝脏中VTG1 mRNA水平升高,在10μg.L-1暴露浓度处与对照组呈现显著性差异,但在高浓度(10和100μg.L-1)处试验结果误差较大;VTG3 mRNA水平只在10μg.L-1暴露浓度处升高,但相比于对照组均没有显著性差异.试验结果表明PFOS暴露对斑马鱼的内分泌干扰作用明显,其毒性作用机制可能是类雌激素效应,而肝脏中VTG1和VTG3mRNA水平可能作为PFOS内分泌干扰效应评价的敏感生物标志物,但VTG1和VTG3 mRNA水平的响应曲线呈现基因亚型和性别差异.

To study the endocrine disrupting effects and action mechanism of environmental levels of perfluorooctane sulfonate(PFOS) on the aquatic species,the research for the effects of PFOS exposure on vitellogenin(VTG) mRNA level in livers of zebrafish(Brachydanio rerio) was conducted.Zebrafish were exposed to PFOS at four environmental low concentrations(0.1,1,10,100 μg·L-1) for 21 days.Livers from male and female zebrafish were collected for RNA extraction,VTG1 and VTG3 mRNA levels were measured respectively using real-time polymerase chain reaction(RT-PCR).The results show that: ① The VTG1 and VTG3 mRNA level in the livers of male zebrafish increased after PFOS exposure.The VTG1 mRNA level increased with a positive dose response pattern,with the maximum response at 100 μg·L-1 PFOS exposure where a significant difference compared with the control was observed.The VTG3 mRNA level increased as an inverted U-shaped dose response pattern,indicated as hormesis effects,where significant differences compared with the control were observed at 10 and 100 μg·L-1 PFOS exposure.② The VTG1 mRNA level in the livers of female zebrafish increased where a significant difference compared with the control was observed at 10 μg·L-1 PFOS exposure,but the standard errors for mRNA level at 10 and 100 μg·L-1 PFOS exposure were distinct.The VTG3 mRNA level in the livers of female zebrafish increased at 10 μg·L-1 PFOS exposure but had no significant difference compared with the control.Thus,it deduced that PFOS exposure could be active on the endocrine system of zebrafish with the oestrogenic simulation action mechanism,and the VTG1 and VTG3 mRNA level in the livers of zebrafish might be sensitive biomarkers for the endocrine disrupting effects evaluation after PFOS exposure,with different responding patterns related to the gene subtypes and sex.