Anastasiadi Dafni, Shao Changwei, Chen Songlin, Piferrer Francesc
Institut de Ciències del Mar, Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain.
Key Lab of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences (CAFS), Qingdao, China.
Mol Ecol. 2021 Feb;30(3):747-760. doi: 10.1111/mec.15764. Epub 2020 Dec 29.
Ocean global warming affects the distribution, life history and physiology of marine life. Extreme events, like marine heatwaves, are increasing in frequency and intensity. During sensitive stages of early fish development, the consequences may be long-lasting and mediated by epigenetic mechanisms. Here, we used European sea bass as a model to study the possible long-lasting effects of a marine heatwave during early development. We measured DNA methylation and gene expression in four tissues (brain, muscle, liver and testis) and detected differentially methylated regions (DMRs). Six genes were differentially expressed and contained DMRs three years after exposure to increased temperature, indicating direct phenotypic consequences and representing persistent changes. Interestingly, nine genes contained DMRs around the same genomic regions across tissues, therefore consisting of common footprints of developmental temperature in environmentally responsive loci. These loci are, to our knowledge, the first metastable epialleles (MEs) described in fish. MEs may serve as biomarkers to infer past life history events linked with persistent consequences. These results highlight the importance of subtle phenotypic changes mediated by epigenetics to extreme weather events during sensitive life stages. Also, to our knowledge, it is the first time the molecular effects of a marine heatwave during the lifetime of individuals are assessed. MEs could be used in surveillance programs aimed at determining the footprints of climate change on marine life. Our study paves the way for the identification of conserved MEs that respond equally to environmental perturbations across species. Conserved MEs would constitute a tool of assessment of global change effects in marine life at a large scale.
海洋全球变暖影响海洋生物的分布、生活史和生理机能。诸如海洋热浪等极端事件的发生频率和强度正在增加。在鱼类早期发育的敏感阶段，其后果可能是持久的，并由表观遗传机制介导。在这里，我们以欧洲海鲈为模型，研究海洋热浪在早期发育过程中可能产生的持久影响。我们测量了四个组织（脑、肌肉、肝脏和睾丸）中的DNA甲基化和基因表达，并检测到差异甲基化区域（DMRs）。在暴露于升高温度三年后，六个基因的表达存在差异且含有DMRs，这表明了直接的表型后果并代表了持续的变化。有趣的是，九个基因在不同组织的相同基因组区域周围含有DMRs，因此构成了环境响应基因座中发育温度的共同印记。据我们所知，这些基因座是鱼类中首次描述的亚稳定表观等位基因（MEs）。MEs可作为生物标志物，用于推断与持久后果相关的过去生活史事件。这些结果突出了表观遗传学介导的微妙表型变化对敏感生命阶段极端天气事件的重要性。此外，据我们所知，这是首次评估海洋热浪在个体生命周期中的分子效应。MEs可用于监测计划，旨在确定气候变化对海洋生物的影响印记。我们的研究为识别对跨物种环境扰动有同等反应的保守MEs铺平了道路。保守的MEs将构成大规模评估海洋生物全球变化影响的工具。
