Belivermiş Murat, Kılıç Önder, Özalp H Barış, Demiralp Selcan, Gezginci-Oktayoglu Selda, Eldem Vahap, Şahin Berna, Balcı Mehmet Ali, Çay Selahattin Barış, Gönülal Onur
Department of Biology, Faculty of Science, Istanbul University, Istanbul, Türkiye.
Department of Biology, Faculty of Science, Istanbul University, Istanbul, Türkiye.
Sci Total Environ. 2025 Aug 15;990:179845. doi: 10.1016/j.scitotenv.2025.179845. Epub 2025 Jun 16.
The Mediterranean gorgonian octocorals are threatened by acidification, warming and marine heat waves. Phenotypic plasticity is critical for slow-growing gorgonians, as adaptation through natural selection might not be fast enough to cope with rapid environmental changes. DNA methylation (DNAm) is a type of (trans)generational phenotypic plasticity mechanism that may help slow-growing corals better withstand the effects of environmental changes by adjusting gene expression. This study aimed to assess the physiological responses and epigenetic modifications associated with phenotypic plasticity in the Mediterranean gorgonians Eunicella singularis and Paramuricea clavata exposed to warming (+4 °C), acidification (-0.35 pH units) and their combination over two weeks. In addition, RNA-Seq-based differential gene expression analysis was performed for E. singularis. High temperature, low pH and their combination did not cause tissue death or necrosis in the corals. Polyp activity in E. singularis increased at high temperatures. Warming increased oxygen consumption in both species. Energy reserves (protein, lipid, carbohydrate contents) were not affected by temperature, pH or their interaction in either species. The global DNA methylation (gDNAm) rate was ten times higher in P. clavata than in E. singularis. There was no effect of temperature, pH or their interaction on gDNAm in E. singularis. gDNAm in P. clavata decreased at high temperatures and low pH. Differential gene expression analysis indicated that high temperature induced the most extensive transcriptional changes in E. singularis, while low pH alone had the least impact. The combined stress of high temperature and low pH also led to notable up- and downregulation of gene expression. Heat stress in E. singularis caused widespread downregulation of transcription factors (TFs), particularly those in the zf-C2H2, AP-2, and HMG families. Conversely, the IRF, RFX, P53, and NRF1 families were upregulated, highlighting the complex transcriptional response to thermal stress. Overall, these physiological, transcriptomic and epigenetic alterations have the potential to negatively impact the fitness of these emblematic species and their associated ecosystems.
地中海柳珊瑚八放珊瑚受到酸化、变暖和海洋热浪的威胁。表型可塑性对于生长缓慢的柳珊瑚至关重要，因为通过自然选择进行适应可能不够快，无法应对快速的环境变化。DNA甲基化（DNAm）是一种（跨）代表型可塑性机制，可能通过调节基因表达帮助生长缓慢的珊瑚更好地抵御环境变化的影响。本研究旨在评估在两周内暴露于升温（+4°C）、酸化（-0.35个pH单位）及其组合条件下，地中海柳珊瑚奇异柳珊瑚（Eunicella singularis）和棒形异柳珊瑚（Paramuricea clavata）中与表型可塑性相关联的生理反应和表观遗传修饰。此外，还对奇异柳珊瑚进行了基于RNA测序的差异基因表达分析。高温、低pH及其组合并未导致珊瑚组织死亡或坏死。奇异柳珊瑚的水螅体活性在高温下增加。升温增加了两个物种的耗氧量。能量储备（蛋白质、脂质、碳水化合物含量）在两个物种中均不受温度、pH或它们之间相互作用的影响。棒形异柳珊瑚的总体DNA甲基化（gDNAm）率比奇异柳珊瑚高十倍。温度、pH或它们之间的相互作用对奇异柳珊瑚的gDNAm没有影响。棒形异柳珊瑚的gDNAm在高温和低pH条件下降低。差异基因表达分析表明，高温在奇异柳珊瑚中诱导了最广泛的转录变化，而单独的低pH影响最小。高温和低pH的联合胁迫也导致了基因表达的显著上调和下调。奇异柳珊瑚中的热应激导致转录因子（TFs）广泛下调，特别是那些属于zf-C2H2、AP-2和HMG家族的转录因子。相反，IRF、RFX、P53和NRF1家族上调，突出了对热应激的复杂转录反应。总体而言，这些生理、转录组和表观遗传改变有可能对这些标志性物种及其相关生态系统的适应性产生负面影响。
