Molecular principles and control of cellular stress responses upon temperature and oxygen stress in Daphnia

了解严重的环境变化(应激源)、应激信号和应激诱导的基因表达之间的因果关系对于理解环境适应和进化适应特别重要。因此，这一应用侧重于应激信号的性质以及应激诱导的基因在水蚤中的表达。应激源、应激信号、转录因子水平和细胞应激反应(转录本和蛋白质水平上的基因表达)之间的关系将以时间分辨的方式在温度和氧气胁迫下进行研究，以分析和理解水蚤细胞应激反应的分子原理和调控。作为实验动物，将使用两种水蚤(普氏水蚤和大型水蚤)，这两种水蚤作为遗传(http://daphnia.cgb.indiana.edu)，)生化或生理模式生物具有独特的实验优势，并且其应激反应动力学的差异已被证明。作为附加项目，将研究应激源、饥饿对应激信号和反应的影响，主要集中在铁代谢和动态平衡，并将调查从头谷胱甘肽与蛋白质合成的关系，以测试蛋白质合成速率增加对抗氧化缓冲能力可能产生的负面影响。

Knowledge of causal connections between severe environmental changes (stressors), stress signaling, and stress-induced gene expressions is particularly important for an understanding of environmental acclimatization and evolutionary adaptation. Consequently, this application focuses on the nature of stress signaling in conjunction with stress-induced gene expressions in Daphnia. The connections between stressors, stress signals, transcription factor levels, and cellular stress responses (gene expressions on transcript and protein levels) will be investigated upon temperature and oxygen stress in a time-resolved manner in order to analyze and understand the molecular principles and control of cellular stress responses in Daphnia. As experimental animals, two Daphnia species (D. pulex and D. magna) will be used, which offer exceptional experimental advantages as genetic (http://daphnia.cgb.indiana.edu), biochemical or physiological model organisms, and for which differences in stress response dynamics have been proven. As add-on projects, effects of the stressor ‚starvation‘ on stress signals and responses will be studied with the main focus on iron metabolism and homeostasis, and the relationship between de novo glutathione and protein syntheses will be investigated to test for possible negative effects of elevated protein synthesis rate on antioxidant buffering capacity.