Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China; College of Chemistry, Biology and Environmental Engineering, Xiangnan University, Chenzhou 423000, PR China.
Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
Sci Total Environ. 2020 Sep 15;735:139373. doi: 10.1016/j.scitotenv.2020.139373. Epub 2020 May 13.
Geosmin (trans-1, 10-dimethyl-trans-9-decalol), a volatile organic compound, has been widely detected in aquatic ecosystems. However, the ecological effects of geosmin are not clear. Here, using zebrafish (Danio rerio) embryo as a model, we investigated biological activity effects of environmentally relevant concentrations (50, 500, 5000 ng/L) of geosmin on the developing zebrafish starting from 2 h post-fertilization (hpf) to 96 hpf. Results showed geosmin had no effect on hatchability, malformations and mortality. However, we observed that geosmin exposure significantly increased zebrafish body length in a concentration dependent manner. This effect was possibly due to up-regulation of expression of genes along the growth hormone/insulin-like growth factor (GH/IGF) axis and hypothalamic-pituitary-thyroid (HPT) axis. In addition, superoxide dismutase (SOD) activities and catalase (CAT) activities significantly increased at 96 hpf when the embryos were exposed to 500 and 5000 ng/L of geosmin. The malondialdehyde (MDA) contents and glutathione S-transferase (GST) activities decreased significantly after the exposure to 5000 ng/L geosmin. Simultaneously, exposure to geosmin resulted in significant increase in cell apoptosis, mainly in the heart area. The mRNA levels of the genes related to oxidative stress and apoptosis were also altered significantly after geosmin exposure. These findings indicated that geosmin can simultaneously induce multiple responses during zebrafish embryonic development, including oxidative stress, apoptosis, and endocrine disruption.
土臭素（反式-1,10-二甲基-反式-9-十二醇）是一种挥发性有机化合物，已广泛存在于水生生态系统中。然而，其生态效应尚不清楚。本研究以斑马鱼（Danio rerio）胚胎为模型，从受精后 2 小时（hpf）到 96 hpf，研究了环境相关浓度（50、500、5000 ng/L）的土臭素对发育中的斑马鱼的生物活性影响。结果表明，土臭素对孵化率、畸形率和死亡率没有影响。然而，我们观察到，土臭素暴露以浓度依赖的方式显著增加了斑马鱼的体长。这种作用可能是由于生长激素/胰岛素样生长因子（GH/IGF）轴和下丘脑-垂体-甲状腺（HPT）轴相关基因的表达上调所致。此外，当胚胎暴露于 500 和 5000 ng/L 的土臭素时，96 hpf 时超氧化物歧化酶（SOD）活性和过氧化氢酶（CAT）活性显著增加。暴露于 5000 ng/L 土臭素后，丙二醛（MDA）含量和谷胱甘肽 S-转移酶（GST）活性显著降低。同时，土臭素暴露导致细胞凋亡显著增加，主要发生在心脏区域。暴露于土臭素后，与氧化应激和细胞凋亡相关的基因的 mRNA 水平也发生了显著改变。这些发现表明，土臭素在斑马鱼胚胎发育过程中可同时诱导多种反应，包括氧化应激、细胞凋亡和内分泌干扰。
