Department of Biology, McMaster University, 1280 Main St. West, Hamilton, ON, L8S 4K1, Canada.
Environ Sci Technol. 2010 Mar 15;44(6):2156-62. doi: 10.1021/es902995q.
This is the first study to implement a genomic approach to ascertain both transcriptional and functional end points of chronic Cu toxicity in fish associated with experimentally manipulated water chemistries. Over 21 d, zebrafish acclimated to softwater (Na(+) = 0.06 mM, Ca(2+) = 0.08 mM, Mg(2+) = 0.03 mM) were exposed to the following: soft-water (Ctrl); 12 microg L(-1) Cu (Cu); 3.3 mM Na(+) (Na); 3.3 mM Na(+) + 12 microg L(-1) Cu (Na + Cu); 3.3 mM Ca(2+) (Ca); or 3.3 mM Ca(2+) + 12 microg L(-1) Cu (Ca + Cu). Although effective at reducing Cu load in all tissues, Na(+) in the presence of Cu did not decrease the degree of oxidative damage, particularly in the gill and gut. In contrast, Ca + Cu treatment decreased Cu accumulation in gill, but not liver or gut, with no reduction in oxidative damage. Transcriptional analysis of candidate genes (atp7a, ctr1, ECaC, esr1) showed principally a down regulation of transcripts with the Cu only treatment, while Ca + Cu treatment restored some of the genes to control levels. Conversely, the Na + Cu treatment had a strong, opposing affect when compared to that of Cu alone. Zebrafish Affymetrix GeneChips revealed significantly clustered patterns of expression. Changes in expression induced by Cu appeared to be opposite to the majority of the other treatments. Our data on the preventative or enhancing effects of Na(+) and Ca(2+) both alone and in the presence of Cu, may, in the future, facilitate the incorporation of gene expression end points into a biotic ligand model predicting chronic Cu toxicity in this tropical model species of genomic importance.
这是首次实施基因组方法来确定与实验性操纵水化学相关的鱼类慢性铜毒性的转录和功能终点的研究。在 21 天的时间里，适应软水（Na(+) = 0.06 mM，Ca(2+) = 0.08 mM，Mg(2+) = 0.03 mM）的斑马鱼暴露于以下环境：软水（对照）；12 微克/升铜（Cu）；3.3 mM Na(+)（Na）；3.3 mM Na(+) + 12 微克/升铜（Na + Cu）；3.3 mM Ca(2+)（Ca）；或 3.3 mM Ca(2+) + 12 微克/升铜（Ca + Cu）。尽管 Na(+) 在存在 Cu 的情况下有效地降低了所有组织中的 Cu 负荷，但并没有降低氧化损伤的程度，尤其是在鳃和肠道中。相比之下，Ca + Cu 处理降低了鳃中的 Cu 积累，但不会降低肝或肠道中的 Cu 积累，也没有降低氧化损伤。候选基因（atp7a、ctr1、ECaC、esr1）的转录分析表明，Cu 单独处理主要下调了转录物，而 Ca + Cu 处理将一些基因恢复到对照水平。相反，与 Cu 单独处理相比，Na + Cu 处理具有强烈的相反作用。斑马鱼 Affymetrix GeneChips 揭示了表达的显著聚类模式。Cu 诱导的表达变化似乎与大多数其他处理相反。我们关于 Na(+) 和 Ca(2+) 单独存在和存在 Cu 时的预防或增强作用的数据，将来可能会促进将基因表达终点纳入预测这种具有基因组重要性的热带模式物种慢性 Cu 毒性的生物配体模型中。
