RNA-Seq of C. elegansof Different Envirometal Induced Dauers

Developmental canalization and plasticity—mechanisms that buffer or enable phenotypic variation—are pervasive features of organismal development. Yet, how these seemingly opposing processes interact remains unclear. The nematode Caenorhabditis elegans offers a powerful model to address this question, as its larvae undergo a dramatic phenotypic switch from continuous growth to a developmentally arrested, phenotypically canalized stage called dauer in response to several distinct environmental and genetic cues. Here, we profiled transcriptomes from five dauer types triggered by different signaling pathways and quantified canalization and plasticity within over 100 gene co-expression networks. We found that, overall, these gene expression networks showed a similar extent of canalization between dauer types, regardless of plasticity, indicating that canalization and plasticity can coexist independently rather than being strictly opposed. However, there were key exceptions: paradoxically, pathways involved in fundamental cellular functions required for dormancy—such as the cell cycle, DNA repair, and energy metabolism—were more canalized the greater the plasticity. Conversely, pathways governing tissue and organ function tended to be less canalized when more plastic. Together, these findings indicate that mechanisms regulating canalization and plasticity of gene expression during C. elegans dauer development are not globally antagonistic but instead act in a modular, pathway- and scale-specific manner. Such an architecture may allow the dauer phenotype to remain developmentally invariant while accommodating pathway-specific variability, enabling survival and adaptability across diverse environments.发育渠化（developmental canalization）与表型可塑性（phenotypic plasticity）——即缓冲或促成表型变异的机制——是生物个体发育的普遍特征。然而，这两种看似对立的过程如何相互作用，目前仍不明确。秀丽隐杆线虫（Caenorhabditis elegans）为解答该问题提供了极佳的研究模型：其幼虫可响应多种不同的环境与遗传信号，经历从持续生长到发育停滞、表型渠化的dauer态（dauer）的剧烈表型转换。本研究对由不同信号通路诱导的5种dauer态样本进行了转录组表征，并对超过100个基因共表达网络（gene co-expression networks）内的渠化程度与可塑性进行了定量分析。研究发现，总体而言，不同dauer态之间的基因表达网络的渠化程度相似，且与可塑性水平无关，这表明发育渠化与表型可塑性可独立共存，而非严格对立。但存在关键例外：反常的是，与休眠所需的基础细胞功能相关的通路（如细胞周期、DNA修复、能量代谢），其可塑性越高，渠化程度反而越强。相反，调控组织与器官功能的通路，其可塑性越高时，渠化程度往往越低。综上，这些研究结果表明，在秀丽隐杆线虫dauer发育过程中，调控基因表达渠化与可塑性的机制并非全局拮抗，而是以模块化、通路特异性和尺度特异性的方式发挥作用。这种架构可使dauer表型在发育层面保持恒定，同时容纳通路特异性的变异，从而帮助生物体在多样环境中实现生存与适应。