Different heat-stress response of field and laboratory cultured Nematostella vectensis

To survive, organisms must deploy a range of molecular, physiological, and behavioral responses to avoid or counteract harmful environmental conditions. Often these responses to environmental stressors are complex, involving many mechanisms and interactions at cellular and organismal levels. Frequently an organism's response to environmental stressors, whether natural or anthropogenic, will involve changes in gene expression and regulation that consequently will alter physiology, development, or behavior. Moreover, animal origin and past growth conditions (e.g., in the field or laboratory) will change its response altogether. In this work, we present and discuss the differences in response to short-term thermal stress of lab-cultured and field-conditioned <i>Nematostella vectensis</i>. Using ATAC-seq and RNA-seq data, we found that the ability to effectively respond to stress is higher in field-conditioned animals, suggesting that acclimation by these animals prepares them to mount an efficient stress response. Field-conditioned animals had a more concentrated reaction, expressed as enrichment of the DNA repair mechanism pathway, while lab animals had a more diffuse reaction that involved a larger number of differentially expressed genes and enriched pathways including amino acid metabolism. Overall, this work presents the importance of experimentally addressing ecological questions in the field as many molecular mechanisms are altered compared to lab conditions.

为维持生存，生物体必须调动一系列分子、生理及行为层面的响应机制，以规避或抵消有害环境条件的影响。这类针对环境胁迫因子的响应往往十分复杂，涉及细胞与个体水平上的多种机制及相互作用。通常而言，无论环境胁迫源于自然过程还是人为活动，生物体对其的响应都会涉及基因表达与调控的改变，进而引发生理、发育或行为层面的变化。此外，动物的起源背景与既往生长环境（例如野外或实验室环境）也会彻底改变其应激响应模式。本研究报道并探讨了实验室培养与野外驯化的星状海葵（Nematostella vectensis）对短期热胁迫的响应差异。通过利用ATAC-seq（转座酶可及性测序）与RNA-seq（RNA测序）数据，我们发现野外驯化个体的有效应激响应能力更强，这表明此类动物的驯化过程可使其具备高效启动应激响应的能力。野外驯化个体展现出更为集中的应激反应，具体体现为DNA修复机制通路的富集；而实验室培养个体的应激反应则更为弥散，涉及更多差异表达基因，且富集通路涵盖氨基酸代谢等类别。总体而言，本研究阐明了在野外环境下开展生态学实验研究的重要性——相较于实验室条件，野外环境下诸多分子机制会发生显著改变。