Marine Science Research Institute of Shandong Province, QingDao, 266104, China.
Marine Science Research Institute of Shandong Province, QingDao, 266104, China.
Comp Biochem Physiol C Toxicol Pharmacol. 2021 Oct;248:109082. doi: 10.1016/j.cbpc.2021.109082. Epub 2021 May 15.
As an important trace metal, nickel (Ni) has been reported extensively in the studies on freshwater animals. However, the toxic effects of Ni on marine organisms are not clearly understood. Therefore, in order to investigate the toxic effects of Ni on the early development of marine fish, the marine medaka (Oryzias melastigma) embryos and larvae were immersed in 0.13-65.80 mg/L Ni solution. The results showed that Ni exposure changed the egg size and heart rate of the embryos, lowered the hatchability, increased the deformity rate, and shortened the total body length of newly hatched larvae. Besides, it was found that before organogenesis and post-hatching periods were the sensitive periods of embryos to Ni. The 25 d LC value of embryos was 49.28 mg/L, and the 5 d LC of larvae was 55.92 mg/L, indicating that the embryos were more sensitive to Ni than the larvae. Furthermore, the expressions of the metallothionein (MT) gene, the skeletal development-related gene (Cyp26b1) and the cardiac development-related genes (ATPase, smyd1, cox2 and bmp4) were determined, and the results showed that the expressions of ATPase and smyd1 were up-regulated, while MT, Cyp26b1 and cox2 were significantly down-regulated at 9 days post-fertilization (dpf). Overall, Ni exposure caused a significant toxic effect on the early development of the O. melastigma embryos and larvae. Our findings could provide an important supplement to the toxicity data of tropical Ni and provide a reference for the exploration of the molecular mechanisms of Ni toxicity.
镍（Ni）作为一种重要的痕量金属，在淡水动物研究中被广泛报道。然而，Ni 对海洋生物的毒性作用尚不清楚。因此，为了研究 Ni 对海洋鱼类早期发育的毒性作用，将海洋斑马鱼（Oryzias melastigma）胚胎和幼鱼浸入 0.13-65.80mg/L 的 Ni 溶液中。结果表明，Ni 暴露改变了胚胎的卵径和心率，降低了孵化率，增加了畸形率，并缩短了刚孵化幼鱼的全长。此外，研究发现器官发生前和孵化后时期是胚胎对 Ni 敏感的时期。胚胎的 25dLC 值为 49.28mg/L，幼鱼的 5dLC 值为 55.92mg/L，表明胚胎比幼鱼对 Ni 更敏感。进一步测定了金属硫蛋白（MT）基因、骨骼发育相关基因（Cyp26b1）和心脏发育相关基因（ATPase、smyd1、cox2 和 bmp4）的表达情况，结果表明，ATPase 和 smyd1 的表达上调，而 MT、Cyp26b1 和 cox2 在受精后 9 天（dpf）时显著下调。总之，Ni 暴露对 O. melastigma 胚胎和幼鱼的早期发育造成了显著的毒性作用。本研究结果可为热带 Ni 的毒性数据提供重要补充，并为探索 Ni 毒性的分子机制提供参考。
