Biogeographic parallels in thermal tolerance and gene expression variation under temperature stress in a widespread bumble bee

Global temperature changes have emphasized the need to understand how species adapt to thermal stress across their ranges. Genetic mechanisms may contribute to variation in thermal tolerance, providing evidence for how organisms adapt to local environments. We determine physiological thermal limits and characterize genome-wide transcriptional changes at these limits in bumble bees using laboratory-reared Bombus vosnesenskii workers. We analyze bees reared from latitudinal (35.7–45.7°N) and altitudinal (7–2154 m) extremes of the species’ range to correlate thermal tolerance and gene expression among populations from different climates. We find that critical thermal minima (CTMIN) exhibit strong associations with local minimums at the location of queen origin, while critical thermal maximum (CTMAX) was invariant among populations. Concordant patterns are apparent in gene expression data, with regional differentiation following cold exposure, and expression shifts invariant among populatio...

全球气候变化凸显了理解物种如何在其分布范围内适应热胁迫（thermal stress）的迫切需求。遗传机制或可介导热耐受性状的变异，为生物适配局地环境提供了理论依据。本研究以实验室饲养的沃氏熊蜂（Bombus vosnesenskii）工蜂为实验材料，测定其生理热极限，并刻画该极限条件下的全基因组转录变化特征。我们选取取自该物种分布范围纬度（35.7°N~45.7°N）与海拔（7m~2154m）极端区域的人工繁育蜂群，旨在关联不同气候区种群的热耐受能力与基因表达模式。研究发现，临界低温极限（critical thermal minima, CTMIN）与蜂王起源地的当地最低温存在显著关联，而临界高温极限（critical thermal maximum, CTMAX）在不同种群间无显著差异。基因表达数据同样呈现出一致的规律：低温暴露后出现显著的种群区域分化，而种群间的表达变化则保持恒定（原文后续内容未完整呈现）。