Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China.
The University of Chinese Academy of Science, Beijing, China.
J Mol Evol. 2022 Oct;90(5):389-399. doi: 10.1007/s00239-022-10070-4. Epub 2022 Aug 27.
High-elevation adaptation provides an excellent system for examining adaptive evolution, and adaptive variations may manifest at gene expression or any other phenotypic levels. We examined gene expression profiles of Asiatic toads (Bufo gargarizans) along an elevational gradient from both wild and common-garden acclimated populations. Asiatic toads originated from high altitudes have distinctive gene expression patterns. We identified 18 fixed differentially expressed genes (DEGs), which are different in both wild and acclimated samples, and 1217 plastic DEGs, which are different among wild samples. The expression levels of most genes were linearly correlated with altitude gradient and down-regulated in high-altitude populations. Expression variations of several genes associated with metabolic process are fixed, and we also identified a co-expression module that is significantly different between acclimated populations and has functions related to DNA repair. The differential expression of the vast majority genes, however, are due to phenotypic plasticity, revealing the highly plastic nature of gene expression variations. Expression modification of some specific genes related to metabolism and response to UV radiation play crucial role in adaptation to high altitude for Asiatic toads. Common-garden experiments are essential for evaluating adaptive evolution of natural populations.
高海拔适应为研究适应性进化提供了一个极好的系统，适应性变化可能表现在基因表达或任何其他表型水平上。我们沿着海拔梯度从野生和常规饲养驯化种群中检查了亚洲蟾蜍（Bufo gargarizans）的基因表达谱。起源于高海拔地区的亚洲蟾蜍具有独特的基因表达模式。我们确定了 18 个固定的差异表达基因（DEG），这些基因在野生和驯化样本中都不同，还有 1217 个可塑的 DEG，这些基因在野生样本中不同。大多数基因的表达水平与海拔梯度呈线性相关，在高海拔种群中下调。与代谢过程相关的几个基因的表达变化是固定的，我们还鉴定了一个在驯化种群之间存在显著差异的共表达模块，该模块具有与 DNA 修复相关的功能。然而，绝大多数基因的差异表达是由于表型可塑性所致，这揭示了基因表达变化的高度可塑性。一些与代谢和对 UV 辐射反应相关的特定基因的表达修饰在亚洲蟾蜍适应高海拔方面起着至关重要的作用。常规饲养实验对于评估自然种群的适应性进化至关重要。
