Population transcriptomes reveal synergistic responses of DNA polymorphism and RNA expression to extreme environments on the Qinghai–Tibetan Plateau in a predatory bird

Low oxygen and temperature pose key physiological challenges for endotherms living on the Qinghai–Tibetan Plateau (QTP). Molecular adaptations to high-altitude living have been detected in the genomes of Tibetans, their domesticated animals and a few wild species, but the contribution of transcriptional variation to altitudinal adaptation remains to be determined. Here we studied a top QTP predator, the saker falcon, and analysed how the transcriptome has become modified to cope with the stresses of hypoxia and hypothermia. Using a hierarchical design to study saker populations inhabiting grassland, steppe/desert and highland across Eurasia, we found that the QTP population is already distinct despite having colonized the Plateau <2000 years ago. Selection signals are limited at the cDNA level, but of only seventeen genes identified, three function in hypoxia and four in immune response. Our results show a significant role for RNA transcription: 50% of upregulated transcription facto...栖息于青藏高原（Qinghai–Tibetan Plateau, QTP）的内温动物（endotherm），面临着低氧与低温这两大核心生理挑战。此前已有研究在藏族人群、其驯养动物以及少数野生物种的基因组中，鉴定出针对高原生存的分子适应性机制，但转录组变异（transcriptional variation）对海拔适应的贡献仍有待阐明。本研究以青藏高原顶级捕食者——矛隼（saker falcon）为研究对象，解析其转录组（transcriptome）如何发生适应性重塑，以应对低氧（hypoxia）与低温（hypothermia）胁迫。研究采用分层实验设计（hierarchical design），对欧亚大陆草原、草原/荒漠及高原等不同生境中的矛隼种群展开调查，结果显示：尽管青藏高原种群仅在不到2000年前便定居于此，但其转录组特征已与其他种群显著分化。在互补DNA（cDNA）层面检测到的选择信号较为有限，仅鉴定出17个相关基因，其中3个参与低氧应答通路，4个参与免疫应答过程。本研究结果证实了RNA转录（RNA transcription）在海拔适应中的关键作用：上调表达的转录因子中……