Temperature is a key environmental factor, and understanding how its fluctuations affect physiological and metabolic processes is critical for fish. The present study characterizes the energy response and fatty acid metabolism in Onychostoma macrolepis exposed to low temperature (10 °C). The results demonstrated that cold stress remarkably disrupted the energy homeostasis of O. macrolepis, then the AMP-activated protein kinase (AMPK) could strategically mobilize carbohydrates and lipids. In particular, when the O. macrolepis were faced with cold stress, the lipolysis was stimulated along with the enhanced fatty acid β-oxidation for energy, while the fatty acid synthesis was supressed in the early stage. Additionally, the fatty acid composition analysis suggested that saturated fatty acid (SFA) might accumulate while monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) in storage lipids (mainly containing non-polar lipid, NPL) could be utilized to supply energy during cold acclimation. Altogether, this study may provide some meritorious for understanding the cold-tolerant mechanism of fish in the viewpoint of energy balance combined with fatty acid metabolism, and thus to contribute to this species rearing in fish farms in the future.

中文翻译：

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低温胁迫下大鳞甲虫的能量反应和脂肪酸代谢

温度是一个关键的环境因素，了解其波动如何影响生理和代谢过程对鱼类至关重要。本研究表征了暴露于低温 (10 °C) 的 Onychostoma macrolepis 的能量反应和脂肪酸代谢。结果表明，冷应激显着破坏了大鳞鱼的能量稳态，然后 AMP 活化蛋白激酶 (AMPK) 可以战略性地动员碳水化合物和脂质。特别是大鳞鱼在低温胁迫下，脂肪分解受到刺激，脂肪酸β-氧化供能增强，而脂肪酸合成则在早期受到抑制。此外，脂肪酸组成分析表明，饱和脂肪酸（SFA）可能积累，而储存脂质（主要含有非极性脂质，NPL）中的单不饱和脂肪酸（MUFA）和多不饱和脂肪酸（PUFA）可用于在寒冷期间提供能量适应。总而言之，本研究可能为从能量平衡结合脂肪酸代谢的角度理解鱼类的耐寒机制提供一些有价值的信息，从而为未来在养鱼场养殖该物种做出贡献。