Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Haidian District, Beijing 100085, China.
University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shijingshan District, Beijing 100049, China.
RNA. 2023 May;29(5):675-690. doi: 10.1261/rna.079319.122. Epub 2023 Feb 21.
Rapid plastic response to environmental changes, which involves extremely complex underlying mechanisms, is crucial for organismal survival during many ecological and evolutionary processes such as those in global change and biological invasions. Gene expression is among the most studied molecular plasticity, while co- or posttranscriptional mechanisms are still largely unexplored. Using a model invasive ascidian , we studied multidimensional short-term plasticity in response to hyper- and hyposalinity stresses, covering the physiological adjustment, gene expression, alternative splicing (AS), and alternative polyadenylation (APA) regulations. Our results demonstrated that rapid plastic response varied with environmental context, timescales, and molecular regulatory levels. Gene expression, AS, and APA regulations independently acted on different gene sets and corresponding biological functions, highlighting their nonredundant roles in rapid environmental adaptation. Stress-induced gene expression changes illustrated the use of a strategy of accumulating free amino acids under high salinity and losing/reducing them during low salinity to maintain the osmotic homoeostasis. Genes with more exons were inclined to use AS regulations, and isoform switches in functional genes such as and resulted in enhanced transporting activities by up-regulating the isoforms with more transmembrane regions. The extensive 3'-untranslated region (3'UTR) shortening through APA was induced by both salinity stresses, and APA regulation predominated transcriptomic changes at some stages of stress response. The findings here provide evidence for complex plastic mechanisms to environmental changes, and thereby highlight the importance of systemically integrating different levels of regulatory mechanisms in studying initial plasticity in evolutionary trajectories.
快速的环境变化响应，涉及到极其复杂的潜在机制，对于生物体在许多生态和进化过程中的生存至关重要，如全球变化和生物入侵过程。基因表达是研究最多的分子可塑性之一，而共转录或后转录机制仍在很大程度上未被探索。我们使用一种模型入侵性海鞘，研究了对高盐度和低盐度胁迫的多维短期可塑性，涵盖了生理调节、基因表达、选择性剪接（AS）和选择性多聚腺苷酸化（APA）调节。我们的结果表明，快速的可塑性响应随环境背景、时间尺度和分子调节水平而变化。基因表达、AS 和 APA 调节独立作用于不同的基因集和相应的生物学功能，突出了它们在快速环境适应中的非冗余作用。应激诱导的基因表达变化表明，在高盐度下积累游离氨基酸，在低盐度下失去/减少它们，以维持渗透平衡。具有更多外显子的基因倾向于使用 AS 调节，而功能基因如 和 的异构体转换导致具有更多跨膜区域的异构体的上调，从而增强了转运活性。广泛的 3'非翻译区（3'UTR）通过 APA 缩短被盐度胁迫诱导，并且 APA 调节在应激反应的某些阶段主导转录组变化。这些发现为环境变化的复杂可塑性机制提供了证据，从而强调了系统整合不同调节机制水平在研究进化轨迹中的初始可塑性的重要性。
