Liu Jian, Yan Guizhen, Huo Zihui, Mo Yucong, Wen Yuting, Liu Weizhen, Zhou Hongyu, Yan Bing, Lin Zhang
School of Environment and Energy, Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, South China University of Technology, Guangzhou, Guangdong 510006, China.
Institute of Environmental Research at Greater Bay Area; Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, Guangdong 510006, China.
Environ Health (Wash). 2024 Feb 7;2(3):114-125. doi: 10.1021/envhealth.3c00196. eCollection 2024 Mar 15.
The escalating frequency of thallium (Tl) contamination incidents amplifies its environmental risk. However, the potential risk of Tl to aquatic organisms, especially across varying developmental stages, remains poorly understood. In this study, we employed zebrafish as a representative model organism and exposed zebrafish embryos and larvae at distinct developmental periods (specifically, 6 h postfertilization (hpf) and 72 hpf) to low concentrations of Tl(I) (0.25 and 0.50 mg/L). The exposure was performed for a short duration of 24 h, followed by a 96 h depuration period. Our results revealed that Tl(I) exerted disparate biological effects on zebrafish at different developmental stages. Embryos exhibited negligible uptake of Tl(I), whereas larvae showed a significant accumulation of Tl(I) and struggled with its rapid elimination. Notably, Tl(I) was able to permeate the blood-brain barrier, thereby posing a risk to the nervous system. Transcriptomic analysis indicated that Tl(I) triggered distinct toxicological pathways in embryos and larvae. It mainly interfered with metabolic processes in embryos, while in larvae, it mainly disrupted intracellular ion homeostasis, both consequently provoking neurotoxicity. This emphasizes that the multifaceted nature of Tl(I) toxicity depends on the developmental stages of the organism. This study clearly shows that the bioeffects of Tl are intricately related to the developmental stage of zebrafish, offering a valuable perspective for the pollutant toxicity assessment.
铊（Tl）污染事件的频率不断上升，加剧了其环境风险。然而，铊对水生生物的潜在风险，尤其是在不同发育阶段的风险，仍知之甚少。在本研究中，我们以斑马鱼作为代表性模式生物，将斑马鱼胚胎和幼虫在不同发育时期（具体为受精后6小时（hpf）和72 hpf）暴露于低浓度的Tl（I）（0.25和0.50 mg/L）。暴露持续24小时，随后是96小时的净化期。我们的结果表明，Tl（I）在不同发育阶段对斑马鱼产生了不同的生物学效应。胚胎对Tl（I）的摄取可忽略不计，而幼虫则表现出Tl（I）的显著积累且难以快速消除。值得注意的是，Tl（I）能够穿透血脑屏障，从而对神经系统构成风险。转录组分析表明，Tl（I）在胚胎和幼虫中引发了不同的毒理学途径。它主要干扰胚胎中的代谢过程，而在幼虫中，它主要破坏细胞内离子稳态，两者均导致神经毒性。这强调了Tl（I）毒性的多面性取决于生物体的发育阶段。这项研究清楚地表明，铊的生物效应与斑马鱼的发育阶段密切相关，为污染物毒性评估提供了有价值的视角。
