Jiang Yuhang, Huang Zhihui, Ma Aijun, Cao Junwen, Zhang Hao, Zhao Yinuo, Hu Yan, Liu Ming
State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, China-ASEAN Belt and Road Joint Laboratory On Mariculture Technology (Qingdao), Qingdao Key Laboratory for Marine Fish Breeding and Biotechnology, No.106 Nanjing Road, Qingdao, 266071, Shandong, China.
Graduate School of Chinese Academy of Agriculture Science, Beijing, 100081, China.
Fish Physiol Biochem. 2025 May 23;51(3):101. doi: 10.1007/s10695-025-01518-7.
The heart is an important factor affecting the upper limit of thermal tolerance in fish, and plays a major role in their physiological plasticity and acclimation to different thermal conditions. Turbot (Scophthalmus maximus (L.)) is a cold-water marine fish, and in our previous studies, selecting a high-temperature resistant strain (HR) which increased the upper limit of high-temperature tolerance by more than 2 °C. The study evaluated the difference of the thermal tolerance between the high-temperature resistant strain (HR) and general group (GG) by using Arrhenius break temperatures (ABT). The ABT between them showed a significant difference that suggested different levels of thermal resistance. The result was consistent with assessments of upper thermal tolerance, as well as the activity of creatine kinase and lactate dehydrogenase. Meanwhile, the key genes regulating cardiac performance were analyzed in molecular level. Quantitative real-time PCR results demonstrated that the RNA expression of β-ARs in the heart at increasing temperature followed an upward trend. However, the expression of mmp2, timp2, fosa, and pcna genes in the heart decreased. Additionally, western blot results demonstrated that the levels of β1-AR and β3-AR protein expression steadily increased. Overall, in response to acute thermal stress, the primary effector genes in the β-AR signalling pathway were β-ARs. Our study identified an effective and accurate measurement for evaluating the turbot's thermal tolerance and initially explored the molecular mechanisms that regulate cardiac performance under thermal stress. These would be greatly beneficial in aquaculture and breeding projects of turbot.
心脏是影响鱼类耐热上限的一个重要因素，在其生理可塑性以及对不同温度条件的适应过程中发挥着主要作用。大菱鲆（Scophthalmus maximus (L.)）是一种冷水性海水鱼类，在我们之前的研究中，选育出了一个耐高温品系（HR），其高温耐受上限提高了2℃以上。本研究通过阿伦尼乌斯断点温度（ABT）评估了耐高温品系（HR）和普通群体（GG）之间的耐热性差异。它们之间的ABT存在显著差异，这表明了不同的耐热水平。该结果与对高温耐受性以及肌酸激酶和乳酸脱氢酶活性的评估结果一致。同时，在分子水平上分析了调节心脏性能的关键基因。定量实时PCR结果表明，随着温度升高，心脏中β-肾上腺素能受体（β-ARs）的RNA表达呈上升趋势。然而，心脏中mmp2、timp2、fosa和pcna基因的表达下降。此外，蛋白质免疫印迹结果表明，β1-AR和β3-AR蛋白表达水平稳步上升。总体而言，在急性热应激反应中，β-AR信号通路中的主要效应基因是β-ARs。我们的研究确定了一种有效且准确的评估大菱鲆耐热性的方法，并初步探索了热应激下调节心脏性能的分子机制。这些对于大菱鲆的水产养殖和育种项目将大有裨益。
