Data from: Thermal adaptation and acclimation of ectotherms from differing aquatic climates

To elucidate the mechanisms of thermal adaptation and acclimation in ectothermic aquatic organisms from differing climates, we used a common-garden experiment for thermal stress to investigate the heat shock response of redband trout (Oncorhynchus mykiss gairdneri) from desert and montane populations. Evidence for adaptation was observed as expression of heat shock genes in fish from the desert population was more similar to control (unstressed) fish and significantly different (P ≤ 0.05) from those from the montane population, while F1 crosses were intermediate. High induction of heat shock proteins (Hsps) in the montane strain appeared to improve short-term survival during first exposure to high water temperatures, but high physiological costs of Hsp production may have led to lower long-term survival. In contrast, the desert strain had significantly lower heat shock response than the montane fish and F1 crosses, suggesting that these desert fish have evolved alternative mechanisms to deal with thermal stress that provide better balance of physiological costs. Genomewide tests of greater than 10 000 SNPs found multiple SNPs that were significantly associated with survival under thermal stress, including Hsp47 which consistently appeared as a strong candidate gene for adaption to desert climates. Candidate SNPs identified in this study are prime targets to screen more broadly across this species' range to predict the potential for adaptation under scenarios of climate change. These results demonstrate that aquatic species can evolve adaptive responses to thermal stress and provide insight for understanding how climate change may impact ectotherms.为阐明不同气候来源的变温水生生物的热适应与热驯化机制，本研究采用热胁迫同质园实验（common-garden experiment），对来自沙漠种群与山地种群的红带鳟（Oncorhynchus mykiss gairdneri）的热休克应答展开研究。研究观察到了适应相关的证据：沙漠种群个体的热休克基因表达模式与对照（未受胁迫）个体更为相似，且与山地种群个体的表达模式存在显著差异（P ≤ 0.05）；而F1杂交子代的表达模式则介于两者之间。山地品系的热休克蛋白（heat shock proteins, Hsps）高诱导表达，似乎可提升初次暴露于高温水体时的短期存活率，但热休克蛋白合成带来的高生理成本，可能导致其长期存活率降低。与之相反，沙漠品系的热休克应答水平显著低于山地种群个体与F1杂交子代，这表明这些沙漠鳟鱼已演化出应对热胁迫的替代机制，能够更优地平衡生理成本。针对超过10000个单核苷酸多态性（Single Nucleotide Polymorphisms, SNPs）的全基因组检验发现，多个与热胁迫下存活率显著相关的单核苷酸多态性位点，其中包括热休克蛋白47（Hsp47）——该基因始终是适应沙漠气候的强候选基因。本研究鉴定出的候选单核苷酸多态性位点，可作为核心筛查靶点在该物种的全分布范围内开展大范围筛查，以预测气候变化情景下物种的适应潜力。本研究结果证实，水生生物可演化出针对热胁迫的适应性响应，同时为理解气候变化如何影响变温动物提供了关键见解。