Abstract：
Atmospheric CO2 and temperature are rising concurrently, and may have profound impacts on the transcriptional, physiological and behavioural responses of aquatic organisms. Further, spring snowmelt may cause transient increases of pCO2 in many freshwater systems. We examined the behavioural, physiological and transcriptomic responses of an ancient fish, the lake sturgeon (Acipenser fulvescens) to projected levels of warming and pCO2 during its most vulnerable period of life, the first year. Specifically, larval fish were raised in either low (16°C) or high (22°C) temperature, and/or low (1000 μatm) or high (2500 μatm) pCO2 in a crossed experimental design over approximately 8 months. Following overwintering, lake sturgeon were exposed to a transient increase in pCO2 of 10,000 μatm, simulating a spring melt based on data in freshwater systems. Transcriptional analyses revealed potential connections to otolith formation and reduced growth in fish exposed to high pCO2 and temperature in combination. Network analyses of differential gene expression revealed different biological processes among the different treatments on the edges of transcriptional networks. Na+/K+-ATPase activity increased in fish not exposed to elevated pCO2 during development, and mRNA abundance of the β subunit was most strongly predictive of enzyme activity. Behavioural assays revealed a decrease in total activity following an acute CO2 exposure. These results demonstrate compensatory and compounding mechanisms of pCO2 and warming dependent on developmental conditions in lake sturgeon. Conserved elements of the cellular stress response across all organisms provide key information for how other freshwater organisms may respond to future climate change.
摘要：
大气二氧化碳和温度同时上升，并可能对转录产生深远的影响，水生生物的生理和行为反应。Further,春季融雪可能会导致许多淡水系统中pCO2的瞬时增加。我们检查了行为，古代鱼类的生理和转录组反应，在其生命中最脆弱的时期，st鱼（AcipenserFulfvescens）达到预期的变暖和pCO2水平，第一年。具体来说,幼鱼在低（16°C）或高（22°C）温度下饲养，和/或在大约8个月的交叉实验设计中的低(1000μatm)或高(2500μatm)pCO2。越冬后，湖鱼暴露于10,000μatm的pCO2瞬时增加，根据淡水系统中的数据模拟春季融化。转录分析揭示了与耳石形成和暴露于高pCO2和温度的鱼类生长减少的潜在联系。差异基因表达的网络分析揭示了转录网络边缘的不同处理之间的不同生物学过程。在发育过程中未暴露于升高的pCO2的鱼类中，Na/K-ATPase活性增加，β亚基的mRNA丰度最能预测酶活性。行为分析显示，急性CO2暴露后总活性降低。这些结果表明，pCO2和变暖的补偿和复合机制取决于湖鱼的发育条件。所有生物的细胞应激反应的保守元素为其他淡水生物如何应对未来的气候变化提供了关键信息。
