Data from: Hsp70 protein levels and thermotolerance in Drosophila subobscura: a reassessment of the thermal co-adaptation hypothesis

Theory predicts that geographic variation in traits and genes associated with climatic adaptation may be initially driven by the correlated evolution of thermal preference and thermal sensitivity. This assumes that an organism’s preferred body temperature corresponds with the thermal optimum in which performance is maximized; hence, shifts in thermal preferences affect the subsequent evolution of thermal-related traits. Drosophila subobscura evolved world-wide latitudinal clines in several traits including chromosome inversion frequencies, with some polymorphic inversions being apparently associated with thermal preference and thermal tolerance. Here we show that flies carrying the warm-climate chromosome arrangement have higher basal protein levels of Hsp70 than their cold-climate counterparts, but this difference disappears after heat hardening. carriers are also more heat tolerant, although it is difficult to conclude from our results that this is causally linked to their higher basal levels of Hsp70. The observed patterns are consistent with the thermal co-adaptation hypothesis, and suggest that the interplay between behaviour and physiology underlies latitudinal and seasonal shifts in inversion frequencies.

理论预测，与气候适应相关的性状和基因的地理变异，最初可能由热偏好（thermal preference）与热敏感性（thermal sensitivity）的协同进化所驱动。该理论假设，生物体的偏好体温与性能最大化的热最适值（thermal optimum）相一致；因此，热偏好的改变会影响后续与热相关性状的进化。亚暗果蝇（Drosophila subobscura）在包括染色体倒位频率在内的多个性状上形成了全球分布的纬度渐变群，其中部分多态性染色体倒位显然与热偏好及热耐受性（thermal tolerance）相关。本研究显示，携带暖气候型染色体倒位的果蝇，其Hsp70（热休克蛋白70）的基础蛋白水平高于冷气候型对应个体，但该差异在热硬化处理（heat hardening）后会消失。携带该倒位的果蝇同样具有更强的热耐受性，但本研究结果尚无法确凿证明该热耐受性与其更高的Hsp70基础蛋白水平存在因果关联。本研究观察到的模式与热协同适应假说（thermal co-adaptation hypothesis）相一致，表明行为与生理之间的相互作用是染色体倒位频率出现纬度及季节变化的内在基础。