Abstract Short-term changes in environmental conditions largely influence planktonic organisms, but their responses will depend on the habitat characteristics. Here we studied diurnal patterns in antioxidative metabolites (lipophilic and hydrophilic antioxidant capacities) and in the expression of stress protein genes (heat shock proteins, hsp) of copepods to identify short-term stress responses in clear and turbid alpine lakes, as well as in less transparent subalpine ones. Cyclops abyssorum tatricus showed diurnal variation in antioxidant capacities with maxima around noon in clear, but not in glacially fed, turbid lakes. Low fluctuations of these metabolites were also observed in another copepod, Acanthodiaptomus denticornis. Although levels of hsp genes differed between populations living in clear or glacially fed lakes, there was no diurnal rhythmicity in gene expression. Our data show that when planktonic organisms may be at greatest risk of oxidative damage, such as during the daytime in high UV radiation environments, they activate antioxidant responses. Conversely, in less transparent lakes, the physiological response seems to be unnecessary. The difference in gene expression levels suggests an ecological, albeit not acute, role of these genes in copepods experiencing daily environmental fluctuations.

中文翻译：

---

对比抗氧化能力的昼夜模式，但在来自清澈湖泊和冰川喂养的高山和亚高山湖泊的桡足类种群中，应激蛋白基因的表达没有

摘要 环境条件的短期变化在很大程度上影响浮游生物，但它们的反应将取决于栖息地特征。在这里，我们研究了桡足类抗氧化代谢物（亲脂性和亲水性抗氧化能力）和应激蛋白基因（热休克蛋白，hsp）的表达的昼夜模式，以识别清澈和浑浊的高山湖泊中的短期应激反应，以及不太透明的亚高山。Cyclops abyssorum tatricus 显示出抗氧化能力的昼夜变化，在晴朗的中午左右达到最大值，但在冰川喂养的浑浊湖泊中则不然。在另一种桡足类动物 Acanthodiaptomus denticornis 中也观察到这些代谢物的低波动。尽管生活在清澈或冰川补给的湖泊中的人群的 hsp 基因水平不同，基因表达没有昼夜节律性。我们的数据表明，当浮游生物可能面临最大的氧化损伤风险时，例如在高紫外线辐射环境中的白天，它们会激活抗氧化反应。相反，在不太透明的湖泊中，生理反应似乎是不必要的。基因表达水平的差异表明这些基因在经历日常环境波动的桡足类动物中的生态作用，尽管不是急性作用。