Resetting thermal limits: 10-year-old white sturgeon display pronounced but reversible thermal plasticity
Resetting thermal limits: 10-year-old white sturgeon display pronounced but reversible thermal plasticity
复制标题
重置热极限：10岁白鲟表现出明显但可逆的热可塑性
DOI：
10.1016/j.jtherbio.2024.103807
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发表时间：
2024
影响因子：
2.7
通讯作者：
Brauner, Colin J.
中科院分区：
文献类型：
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作者：
Weber, Theresa A.;Dichiera, Angelina M.;Brauner, Colin J.
虽然许多外温动物提高热耐受性，以应对长期的热应激，很少有人知道的持久影响后，返回到较冷的温度温暖驯化。此外，热应力可能对受威胁和濒危物种造成不成比例的影响。为了解决这个问题，我们反复测量临界热最大值，（CTmax; °C）和相关的压力反应濒危亚成体白色鲟鱼的红细胞压积、血红蛋白浓度、血浆皮质醇（Acipenser transmontanus）对控制温度的反应（适应前; 14°C），在对照或温暖温度下1个月后（驯化; 14°C或20°C），以及在恢复到对照温度后一个月（驯化后; 14°C）。虽然对照鱼表现出相当可重复的热耐受性（类间相关系数= 0.479），但温暖驯化的鱼的热耐受性增加了3.1°C，当重新适应控制温度时，热耐受性降低了1.9°C。红细胞压积，血红蛋白浓度，和最终的脾脏体细胞指数（脾脏质量相对于全身质量，收集后驯化CTmax）之间没有显着差异的控制和治疗鱼，表明没有影响的热驯化有氧能力。血浆皮质醇显着较高的控制鱼后，驯化前和驯化后CTmax试验，但重要的是，驯化温度并不影响这种反应。引人注目的是，最终hepatosomatic指数（相对肝脏大小）是45%，治疗鱼，表明温暖的驯化可能有持久的影响，能量的使用和代谢，即使在reaculating控制温度。据我们所知，这些10岁的亚成体鲟鱼是最古老的鲟鱼实验测试的热塑性方面，并表现出令人难以置信的能力，热驯化相对于其他鱼类。然而，还需要更多的研究来确定适应温暖温度的能力是否会带来持续的成本。
While many ectotherms improve thermal tolerance in response to prolonged thermal stress, little is known about the lasting effects of warm acclimation after returning to cooler temperatures. Furthermore, thermal stress may disproportionately impact threatened and endangered species. To address this, we repeatedly measured critical thermal maxima (CTmax; °C) and associated stress responses (hematocrit, hemoglobin concentration, plasma cortisol) of endangered subadult white sturgeon (Acipenser transmontanus) in response to control temperature (pre-acclimation; 14°C), after 1 month at either control or warm temperature (acclimation; 14°C or 20°C), and after one smonth following return to control temperature (post-acclimation; 14°C). While control fish demonstrated fairly repeatable thermal tolerance (interclass correlation coefficient = 0.479), warm-acclimated fish experienced a ∼3.1°C increase in thermal tolerance and when re-acclimated to control temperature, decreased thermal tolerance ∼1.9°C. Hematocrit, hemoglobin concentration, and final splenic somatic index (spleen mass relative to whole body mass, collected after post-acclimation CTmax) were not significantly different between control and treatment fish, suggesting no effects of warm acclimation on aerobic capacity. Plasma cortisol was significantly higher in control fish after pre-acclimation and post-acclimation CTmaxtrials, but importantly, acclimation temperature did not affect this response. Strikingly, final hepatosomatic index (relative liver size) was 45% lower in treatment fish, indicating warm acclimation may have lasting effects on energy usage and metabolism, even after reacclimating to control temperature. To our knowledge, these 10-year-old subadult sturgeon are the oldest sturgeon experimentally tested with regards to thermal plasticity and demonstrate incredible capacity for thermal acclimation relative to other fishes. However, more research is needed to determine whether the ability to acclimate to warm temperature may come with a persistent cost.