Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 91057, Evry, France.
Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/ Tara Oceans-GOSEE, 3 rue Michel-Ange, 75016, Paris, France.
Nat Commun. 2023 Jun 1;14(1):3056. doi: 10.1038/s41467-023-38610-6.
Heat waves are causing declines in coral reefs globally. Coral thermal responses depend on multiple, interacting drivers, such as past thermal exposure, endosymbiont community composition, and host genotype. This makes the understanding of their relative roles in adaptive and/or plastic responses crucial for anticipating impacts of future warming. Here, we extracted DNA and RNA from 102 Pocillopora colonies collected from 32 sites on 11 islands across the Pacific Ocean to characterize host-photosymbiont fidelity and to investigate patterns of gene expression across a historical thermal gradient. We report high host-photosymbiont fidelity and show that coral and microalgal gene expression respond to different drivers. Differences in photosymbiotic association had only weak impacts on host gene expression, which was more strongly correlated with the historical thermal environment, whereas, photosymbiont gene expression was largely determined by microalgal lineage. Overall, our results reveal a three-tiered strategy of thermal acclimatization in Pocillopora underpinned by host-photosymbiont specificity, host transcriptomic plasticity, and differential photosymbiotic association under extreme warming.
热浪正在导致全球范围内的珊瑚礁减少。珊瑚的热响应取决于多个相互作用的驱动因素，如过去的热暴露、共生体群落组成和宿主基因型。这使得理解它们在适应和/或塑性响应中的相对作用对于预测未来变暖的影响至关重要。在这里，我们从太平洋 11 个岛屿的 32 个地点采集的 102 株 P. 属珊瑚中提取了 DNA 和 RNA，以描述宿主-共生体的保真度，并研究了跨越历史热梯度的基因表达模式。我们报告了高宿主-共生体保真度，并表明珊瑚和微藻基因表达对不同的驱动因素有反应。光合共生体的差异对宿主基因表达的影响很小，而宿主基因表达与历史热环境的相关性更强，而微藻的基因表达主要由微藻的谱系决定。总的来说，我们的结果揭示了 P. 属珊瑚在极端变暖条件下的热驯化的三层策略，其基础是宿主-共生体的特异性、宿主转录组的可塑性和不同的光合共生体的关联。
