Symbiont shuffling induces differential DNA methylation responses to thermal stress in the coral Montastraea cavernosa
Symbiont shuffling induces differential DNA methylation responses to thermal stress in the coral Montastraea cavernosa
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DOI：
10.1111/mec.16246
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发表时间：
2021-10
影响因子：
4.9
通讯作者：
Javier A. Rodríguez-Casariego;R. Cunning;A. Baker;J. Eirín-López
中科院分区：
文献类型：
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作者：
Javier A. Rodríguez-Casariego;R. Cunning;A. Baker;J. Eirín-López
藻类共生体的洗牌有利于更耐热的物种，已被证明提高了珊瑚对高温胁迫的抵抗力。然而，人们对这些变化的机制基础和长期影响知之甚少。这项工作研究了珊瑚DNA甲基化的修饰，这是一种参与珊瑚驯化的表观遗传机制，以响应共生体操纵和随后的热应激暴露。在大型星状珊瑚Montastraea cavernosa中，通过受控的热漂白和恢复，共生体的组成被操纵，产生由其本土共生体(Cladocopium)或耐热物种(Durusddium Trenchi)主导的三个属的成对分株。单碱基全基因组分析显示，DNA甲基化的显著修改集中在基因间隔区、内含子和转座元件。值得注意的是，对热应激的DNA甲基化变化取决于优势共生体，与所有其他比较相比，在热应激珊瑚中发现的差异甲基化区域是拥有不同共生体的珊瑚的两倍。有趣的是，尽管差异基因体甲基化与基因表达无关，但在重复基因组区域，差异甲基化区域的丰富是明显的。总体而言，这些结果表明，有利于耐热联想的藻类共生体的变化伴随着珊瑚宿主DNA甲基化的变化。本工作讨论了这些结果对珊瑚适应的影响，以及基于当前知识差距的未来研究途径。
Algal symbiont shuffling in favour of more thermotolerant species has been shown to enhance coral resistance to heat‐stress. Yet, the mechanistic underpinnings and long‐term implications of these changes are poorly understood. This work studied the modifications in coral DNA methylation, an epigenetic mechanism involved in coral acclimatization, in response to symbiont manipulation and subsequent heat stress exposure. Symbiont composition was manipulated in the great star coral Montastraea cavernosa through controlled thermal bleaching and recovery, producing paired ramets of three genets dominated by either their native symbionts (genus Cladocopium) or the thermotolerant species (Durusdinium trenchi). Single‐base genome‐wide analyses showed significant modifications in DNA methylation concentrated in intergenic regions, introns and transposable elements. Remarkably, DNA methylation changes in response to heat stress were dependent on the dominant symbiont, with twice as many differentially methylated regions found in heat‐stressed corals hosting different symbionts (Cladocopium vs. D. trenchii) compared to all other comparisons. Interestingly, while differential gene body methylation was not correlated with gene expression, an enrichment in differentially methylated regions was evident in repetitive genome regions. Overall, these results suggest that changes in algal symbionts favouring heat tolerant associations are accompanied by changes in DNA methylation in the coral host. The implications of these results for coral adaptation, along with future avenues of research based on current knowledge gaps, are discussed in the present work.