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.