Inner Mongolia Key Laboratory of Toxicant Monitoring and Toxicology, College of Animal Science and Technology, Inner Mongolia University for the Nationalities, Tongliao, Inner Mongolia 028000, China; School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore; Nanyang Environment and Water Research Institute, Nanyang Technological University, 637141, Singapore.
Inner Mongolia Key Laboratory of Toxicant Monitoring and Toxicology, College of Animal Science and Technology, Inner Mongolia University for the Nationalities, Tongliao, Inner Mongolia 028000, China; Laboratory of Developmental Nutrition, Department of Animal Sciences, North Carolina State University, Raleigh, NC 27695, USA.
Environ Int. 2020 Jun;139:105705. doi: 10.1016/j.envint.2020.105705. Epub 2020 Apr 10.
The application of tetracycline (TET) is very common in medical treatment, fisheries, and animal husbandry, resulting in its frequent detection with abundant concentrations in the aquatic environment. Though the effects of TET on zebrafish (Danio rerio) at embryonic and larval stages have been reported, there is very limited information on the possible long-term effect on aquatic fishes at the juvenile stage, especially at environmentally relevant levels. In this study, we have exposed juvenile zebrafish to two levels of TET at 1 and 100 µg/L for one month until their adulthood. The result showed that both levels of TET can significantly increase the body weight of the zebrafish, while there is no change in the body length. TET exposure also affected the liver microstructure by lipid vacuoles generation and global lipidomics analysis revealed a significant upregulation in hepatic triglyceride (TAG) levels. The metabolomics analysis showed great dysregulations in hepatic metabolic pathways including linoleic acid metabolism, tyrosine metabolism, and methionine metabolism, which are known to be linked with increased body weight gain through hepatic lipid accumulation. The hepatic gene expression involved in lipid transport (e.g., apoa4 and fabp11) and lipogenic factors (e.g., ppar) have been significantly upregulated in the livers of TET exposed zebrafish. Interestingly, the 16 rRNA gene sequence-based zebrafish gut microbial community analysis revealed an enhanced community diversity and altered microbial community composition upon TET exposure. To our knowledge, this is the first study showing that TET exposure can increase the body weight in juvenile zebrafish and the study on the ecotoxicity of antibiotic occurrences in the aquatic system can be further warranted.
四环素（TET）在医学治疗、渔业和畜牧业中的应用非常普遍，导致其在水环境中经常被大量检出。尽管已有报道称 TET 对斑马鱼（Danio rerio）的胚胎和幼虫阶段有影响，但关于其在幼鱼阶段（尤其是在环境相关水平下）对水生鱼类可能产生的长期影响的信息却非常有限。在这项研究中，我们将幼年斑马鱼暴露于 1 和 100 µg/L 的两种 TET 水平下一个月，直至其成年。结果表明，两种 TET 水平均可显著增加斑马鱼的体重，而体长没有变化。TET 暴露还通过产生脂质空泡影响肝脏的微观结构，并且通过全局脂质组学分析发现肝三酰甘油（TAG）水平显著上调。代谢组学分析表明，肝脏代谢途径（如亚油酸代谢、酪氨酸代谢和蛋氨酸代谢）出现了严重的失调，这些途径已知通过肝脂质积累与体重增加有关。与脂质转运（如 apoA4 和 Fabp11）和生脂因子（如 ppar）相关的肝脏基因表达在 TET 暴露的斑马鱼肝脏中显著上调。有趣的是，基于 16S rRNA 基因序列的斑马鱼肠道微生物群落分析显示，TET 暴露后肠道微生物群落的多样性增强，群落组成发生改变。据我们所知，这是第一项表明 TET 暴露可增加幼年斑马鱼体重的研究，进一步证明了抗生素在水生系统中出现的生态毒性研究是有必要的。
