The red cusk-eel (Genypterus chilensis) is a native species with strong potential to support Chilean aquaculture diversification. Environmental stressors, such as temperature, may generate important effects in fish physiology with negative impact. However, no information exists on the effects of thermal stress in Genypterus species or how this stressor affects the skeletal muscle. The present study evaluated for the first time the effect of high temperature stress in red cusk-eel juveniles to determine changes in plasmatic markers of stress (cortisol, glucose and lactate dehydrogenase (LDH)), the transcriptional effect in skeletal muscle genes related to (i) heat shock protein response (hsp60 and hsp70), (ii) muscle atrophy and growth (foxo1, foxo3, fbxo32, murf-1, myod1 and ddit4), and (iii) oxidative stress (cat, sod1 and gpx1), and evaluate the DNA damage (AP sites) and peroxidative damage (lipid peroxidation (HNE proteins)) in this tissue. Thermal stress generates a significant increase in plasmatic levels of cortisol, glucose and LDH activity and induced heat shock protein transcripts in muscle. We also observed an upregulation of atrophy-related genes (foxo1, foxo3 and fbxo32) and a significant modulation of growth-related genes (myod1 and ddit4). Thermal stress induced oxidative stress in skeletal muscle, as represented by the upregulation of antioxidant genes (cat and sod1) and a significant increase in DNA damage and lipid peroxidation. The present study provides the first physiological and molecular information of the effects of thermal stress on skeletal muscle in a Genypterus species, which should be considered in a climate change scenario.

中文翻译：

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红鳗（Genypterus chilensis）幼鱼对热应激的生理和分子反应揭示了骨骼肌的萎缩和氧化损伤

红鳗（Genypterus chilensis）是一种本地物种，具有支持智利水产养殖多样化的强大潜力。环境压力因素，如温度，可能会对鱼类生理产生重要影响，产生负面影响。然而，没有关于热应激对 Genypterus 物种的影响或这种应激源如何影响骨骼肌的信息。本研究首次评估了高温应激对红鲈幼鱼的影响，以确定应激的血浆标志物（皮质醇、葡萄糖和乳酸脱氢酶 (LDH)）的变化，骨骼肌基因的转录作用与（ i) 热休克蛋白反应（hsp60 和 hsp70），（ii）肌肉萎缩和生长（foxo1、foxo3、fbxo32、murf-1、myod1 和 ddit4），以及（iii）氧化应激（cat、sod1 和 gpx1），并评估该组织中的 DNA 损伤（AP 位点）和过氧化损伤（脂质过氧化（HNE 蛋白））。热应激会显着增加皮质醇、葡萄糖和 LDH 活性的血浆水平，并在肌肉中诱导热休克蛋白转录。我们还观察到萎缩相关基因（foxo1、foxo3 和 fbxo32）的上调和生长相关基因（myod1 和 ddit4）的显着调节。热应激诱导骨骼肌氧化应激，表现为抗氧化基因（cat 和 sod1）的上调以及 DNA 损伤和脂质过氧化的显着增加。本研究提供了热应激对 Genypterus 物种骨骼肌影响的第一个生理和分子信息，应在气候变化情景中加以考虑。