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，本研究采用热胁迫共同花园实验（common-garden experiment），探究了来自沙漠与山地种群的红带鳟（Oncorhynchus mykiss gairdneri）的热休克响应。研究观测到适应相关的分子证据：沙漠种群个体的热休克基因表达模式与对照（未受胁迫）个体更为接近，且与山地种群个体存在显著统计学差异（P ≤ 0.05）；而F1杂交个体的表达水平则介于两者之间。山地品系的热休克蛋白（heat shock proteins, Hsps）高诱导表达，看似可提升其首次暴露于高温水体时的短期存活率，但热休克蛋白合成所带来的高额生理成本，可能导致其长期存活率下降。与之相反，沙漠品系的热休克响应强度显著低于山地种群与F1杂交个体，这表明这些沙漠鱼类已演化出兼顾生理成本的替代性热胁迫应对策略。针对超过10000个单核苷酸多态性（single nucleotide polymorphisms, SNPs）的全基因组筛查发现，多个位点与热胁迫下的存活率显著相关，其中Hsp47始终是适应沙漠气候的强势候选基因。本研究鉴定出的候选单核苷酸多态性位点，可作为在该物种全分布范围内开展更广泛筛查的核心靶点，以预测气候变化情景下其环境适应潜能。上述研究结果证实，水生生物能够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生物提供了重要理论参考。