Serén Nina, Pinho Catarina, Megía-Palma Rodrigo, Aguilar Prem, Žagar Anamarija, Andrade Pedro, Carretero Miguel A
CIBIO, Centro de Investigação em Biodiversidade e Recursos Geneticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, Vairão, Portugal.
BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, Vairão, Portugal.
Evol Lett. 2024 Sep 22;9(1):41-50. doi: 10.1093/evlett/qrae047. eCollection 2025 Feb.
High altitude imposes several extreme constraints on life, such as low oxygen pressure and high levels of ultraviolet radiation, which require specialized adaptations. Many studies have focused on how endothermic vertebrates respond to these challenging environments, but there is still uncertainty on how ectotherms adapt to these conditions. Here, we used whole-genome sequencing of low-altitude (100-600 m) and high-altitude (3,550 m) populations of the wide-ranging Tenerife lizard to uncover signatures of selection for altitudinal adaptation. The studied populations show reduced differentiation, sharing similar patterns of genetic variation. Selective sweep mapping suggests that signatures of adaptation to high altitude are not widespread across the genome, clustering in a relatively small number of genomic regions. One of these regions contains , a gene involved with vascular remodeling, and that has been associated with hypoxia-induced angiogenic response. By genotyping samples across 2 altitudinal transects, we show that allele frequency changes at this locus are not gradual, but rather show a well-defined shift above ca. 1,900 m. Transcript and protein structure analyses on this gene suggest that putative selection likely acts on noncoding variation. These results underline how low oxygen pressure generates the most consistent selective constraint in high-altitude environments, to which vertebrates with vastly contrasting physiological profiles need to adapt in the context of ongoing climate change.
高海拔对生命施加了若干极端限制，如低氧压力和高水平的紫外线辐射，这需要特殊的适应性变化。许多研究聚焦于恒温脊椎动物如何应对这些具有挑战性的环境，但对于变温动物如何适应这些条件仍存在不确定性。在此，我们对分布广泛的特内里费岛蜥蜴的低海拔（100 - 600米）和高海拔（3550米）种群进行了全基因组测序，以揭示海拔适应性选择的特征。所研究的种群显示出分化减少，具有相似的遗传变异模式。选择性扫描图谱表明，对高海拔的适应性特征在基因组中并不广泛分布，而是聚集在相对较少的基因组区域。其中一个区域包含 ，一个与血管重塑有关的基因，并且该基因与缺氧诱导的血管生成反应相关。通过对两个海拔断面的样本进行基因分型，我们表明该位点的等位基因频率变化并非渐进的，而是在约1900米以上呈现出明确的转变。对该基因的转录本和蛋白质结构分析表明，推定的选择可能作用于非编码变异。这些结果强调了低氧压力如何在高海拔环境中产生最一致的选择限制，在当前气候变化的背景下，生理特征差异极大的脊椎动物需要适应这一限制。
