摘要:
双酚AF(4,4'-六氟-2-二酚，BPAF)应用渐为广泛，对生态环境具有潜在威胁。为探究BPAF对水生生物的神经毒性，选择斑马鱼作为实验对象，利用T型迷宫和实时定量PCR的研究方法，考察0、0.005、0.05和0.5 mg·L-1 3种不同浓度BPAF暴露下，成年斑马鱼的学习记忆能力，并检测鱼脑中胶质纤维酸性蛋白基因(glial fibrillary acidic protein, gfap)、音猬基因(sonic hedgehog, shha)和突触蛋白基因(synapsinⅡa, syn2a)表达量变化。结果表明：在T迷宫行为学检测中，0.5 mg·L-1 BPAF暴露浓度下，斑马鱼在第1天进入T型迷宫规定臂的潜伏时间与对照组相比显著增加(P<0.01)，随着暴露浓度和染毒时间的增加，潜伏时间显著延长，具有明显的剂效和时效关系。暴露6 d后，BPAF各暴露浓度组中雌鱼脑部gfap基因显著上调，雄鱼脑中gfap基因在高浓度暴露组(0.5 mg·L-1)下表达量下调，而在0.005 mg·L-1 BPAF暴露组差异不明显。BPAF暴露可导致雌鱼脑部shha基因下调，使雄鱼脑中shha基因表达量随暴露浓度增大呈先上升后下降的趋势。BPAF各暴露浓度组中雌鱼和雄鱼脑部syn2a基因下调，呈现出随暴露浓度增大而下降的趋势。综上，初步认为BPAF对斑马鱼具有潜在的神经认知干扰效应。
Abstract:
Bisphenol AF (4,4'-hexafluoro-2-bisphenol, BPAF) is a kind of chemical substrate mainly used to synthesize some fluorocarbon elastomer as cross linker or synthesize special polymers. In order to study the effect of BPAF on neurological system of aquatic organisms, we designed and carried out an experimental study with zebrafish as a model organism. The adult zebrafish was exposed to a gradient of BPAF as 0 (the control), 0.005, 0.05, and 0.5 mg·L-1. The learning and memory behavior and gene expression (glial fibrillary acidic protein gene, sonic hedgehog gene, synapsin II a gene) of zebrafish under different treatment were studied with the T-maze experiment and PCR. The results showed that in the T-maze behavior test, with the exposure of 0.5 mg·L-1 concentration of BPAF, the latency time of zebrafish at entering specified arms of T-maze on the first day increased significantly compared to the control. And the latency time of all the BPAF exposure groups increased significantly with the increase of exposure concentration and the extension of exposure time. After six-day exposure, all BPAF treatments have a significant increase on gfap gene expression in female zebrafish brain, but a decrease for male ones under high BPAF (0.5 mg·L-1). BPAF exposure can lead to the decrease of shha gene expression in the female fish brain, while the shha gene expression first increased and then decreased in male fish brain with the BPAF concentration increasing. In all BPAF exposure groups, a decrease of the syn2a gene expression in zebrafish brain was observed, showing a tendency to decrease with the increase of exposure concentration. Overall, it is indicated that BPAF has potential effect on neural cognition of zebrafish.
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