Cadmium (Cd) poses significant risks to aquatic organisms due to its toxicity and ability to disrupt the cellular processes. Given the similar atomic radius of Cd and calcium (Ca), Cd may potentially affect the Ca homeostasis, which can lead to impaired mineralization of skeletal structures and behavioral abnormalities. The formation of the spinal skeleton involves Ca transport and mineralization. In this study, we conducted an in-depth investigation on the effects of Cd at environmental concentrations on zebrafish (Danio rerio) skeletal development and the underlying molecular mechanisms. As the concentration of Cd increased, the accumulation of Cd in zebrafish larvae also rose, while the Ca content decreased significantly by 3.0 %−57.3 %, and vertebral deformities were observed. Transcriptomics analysis revealed that sixteen genes involved in metal absorption were affected. Exposure to 2 µg/L Cd significantly upregulated the expression of these genes, whereas exposure to 10 µg/L resulted in their downregulation. Consequently, exposure of zebrafish larvae to 10 µg/L of Cd inhibited the body segmentation growth and skeletal mineralization development by 29.1 %−56.7 %. This inhibition was evidenced by the downregulation of mineral absorption genes and decreased Ca accumulation. The findings of this study suggested that the inhibition of skeletal mineralization was likely attributed to the disruption of mineral absorption, thus providing novel insights into the mechanisms by which metal pollutants inhibit the skeletal development of fish.

中文翻译：

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镉对斑马鱼钙矿化、骨骼发育和行为障碍的影响


镉 （Cd） 由于其毒性和破坏细胞过程的能力，对水生生物构成重大风险。鉴于 Cd 和钙 （Ca） 的原子半径相似，Cd 可能会影响 Ca 稳态，从而导致骨骼结构矿化受损和行为异常。脊柱骨骼的形成涉及 Ca 运输和矿化。在这项研究中，我们对环境浓度下 Cd 对斑马鱼 （Danio rerio） 骨骼发育的影响及其潜在的分子机制进行了深入研究。随着 Cd 浓度的增加，斑马鱼幼虫体内 Cd 的积累量也增加，而 Ca 含量显著降低 3.0 %−57.3 %，并观察到椎体畸形。转录组学分析显示，参与金属吸收的 16 个基因受到影响。暴露于 2 μg/L Cd 会显著上调这些基因的表达，而暴露于 10 μg/L 会导致它们下调。因此，斑马鱼幼虫暴露于 10 μg/L 的 Cd 中抑制了身体分段生长和骨骼矿化发育 29.1 %−56.7 %。矿物质吸收基因的下调和 Ca 积累的减少证明了这种抑制。本研究的结果表明，骨骼矿化的抑制可能归因于矿物质吸收的破坏，从而为金属污染物抑制鱼类骨骼发育的机制提供了新的见解。