She Huishang, Hao Yan, Song Gang, Luo Xu, Lei Fumin, Zhai Weiwei, Qu Yanhua
Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
Faculty of Biodiversity and Conservation, Southwest Forestry University, Kunming, China.
Elife. 2024 Mar 12;12:RP86687. doi: 10.7554/eLife.86687.
Phenotypic plasticity facilitates organismal invasion of novel environments, and the resultant phenotypic change may later be modified by genetic change, so called 'plasticity first.' Herein, we quantify gene expression plasticity and regulatory adaptation in a wild bird (Eurasian Tree Sparrow) from its original lowland (ancestral stage), experimentally implemented hypoxia acclimation (plastic stage), and colonized highland (colonized stage). Using a group of co-expressed genes from the cardiac and flight muscles, respectively, we demonstrate that gene expression plasticity to hypoxia tolerance is more often reversed than reinforced at the colonized stage. By correlating gene expression change with muscle phenotypes, we show that colonized tree sparrows reduce maladaptive plasticity that largely associated with decreased hypoxia tolerance. Conversely, adaptive plasticity that is congruent with increased hypoxia tolerance is often reinforced in the colonized tree sparrows. Genes displaying large levels of reinforcement or reversion plasticity (i.e. 200% of original level) show greater genetic divergence between ancestral and colonized populations. Overall, our work demonstrates that gene expression plasticity at the initial stage of high-elevation colonization can be reversed or reinforced through selection-driven adaptive modification.
表型可塑性促进生物体对新环境的入侵，而由此产生的表型变化随后可能会被基因变化所改变，即所谓的“可塑性优先”。在此，我们对一种野生鸟类（家麻雀）在其原始低地（祖先阶段）、实验性实施的低氧驯化（可塑性阶段）和定居高地（定居阶段）的基因表达可塑性和调控适应性进行了量化。分别使用一组来自心脏和飞行肌肉的共表达基因，我们证明在定居阶段，对低氧耐受性的基因表达可塑性更多地是被逆转而非增强。通过将基因表达变化与肌肉表型相关联，我们表明定居的麻雀减少了与低氧耐受性降低密切相关的适应不良可塑性。相反，与增加的低氧耐受性相一致的适应性可塑性在定居的麻雀中常常得到增强。显示出大量增强或逆转可塑性水平（即原始水平的200%）的基因在祖先群体和定居群体之间表现出更大的遗传差异。总体而言，我们的工作表明，在高海拔定居的初始阶段，基因表达可塑性可以通过选择驱动的适应性修饰而被逆转或增强。
