Contaminants are increasingly accumulating in aquatic environments and biota, with potential adverse effects on individual organisms, communities and ecosystems. However, studies that explore the molecular changes in fish caused by environmentally relevant concentrations of metals, such as copper (Cu), are limited. This study uses embryos of the model organism zebrafish () to investigate effect of Cu on the proteome and amino acid (AA) composition of fish. Wild-type embryos at 24 h post-fertilisation were exposed to Cu (2 µg L to 120 µg L) for 96 h and the number of healthy larvae were determined based on larvae that had hatched and did not display loss of equilibrium (LOE). The effect concentrations where Cu caused a 10 % (EC) or 50 % (EC) decrease in the number of healthy larvae were calculated as 3.7 µg L and 10.9 µg L, respectively. Proteomics analysis of embryos exposed to the EC and EC concentrations of Cu revealed the proteome to differ more strongly after 48 h than 96 h, suggesting the acclimatisation of some larvae. Exposure to excess Cu caused differentially expressed proteins (DEPs) involved in oxidative stress, mitochondrial respiration, and neural transduction as well as the modulation of the AAs (Proline, Glycine and Alanine). This is the first study to suggest that LOE displayed by Cu-stressed fish may involve the disruption to GABAergic proteins and the calcium-dependent inhibitory neurotransmitter GABA. Moreover, this study highlights that proteomics and AA analysis can be used to identify potential biomarkers for environmental monitoring.

中文翻译：

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环境相关铜浓度诱导斑马鱼幼虫蛋白质组的分子变异


污染物在水生环境和生物群中不断积累，对个体生物体、群落和生态系统产生潜在的不利影响。然而，探索铜 (Cu) 等环境相关金属浓度引起的鱼类分子变化的研究有限。本研究利用模式生物斑马鱼 () 的胚胎来研究铜对鱼类蛋白质组和氨基酸 (AA) 组成的影响。受精后 24 小时的野生型胚胎暴露于 Cu（2 µg L 至 120 µg L）96 小时，并根据已孵化且未表现出失去平衡 (LOE) 的幼虫确定健康幼虫的数量。 。 Cu 导致健康幼虫数量减少 10% (EC) 或 50% (EC) 的效应浓度分别计算为 3.7 µg·L 和 10.9 µg·L 。对暴露于 EC 和 EC 浓度 Cu 的胚胎进行的蛋白质组学分析显示，48 小时后的蛋白质组差异比 96 小时更强烈，表明一些幼虫已适应环境。暴露于过量的铜会导致差异表达蛋白（DEP）参与氧化应激、线粒体呼吸、神经转导以及 AA（脯氨酸、甘氨酸和丙氨酸）的调节。这是第一项表明铜胁迫鱼表现出的 LOE 可能涉及 GABA 能蛋白和钙依赖性抑制性神经递质 GABA 破坏的研究。此外，这项研究强调蛋白质组学和 AA 分析可用于识别环境监测的潜在生物标志物。