UMR250/9220 ENTROPIE (IRD-CNRS-UR-IFREMER-UNC), Promenade Roger-Laroque, Noumea Cedex, New Caledonia.
Ecole Doctorale 129, SU Sorbonne Université, 4, Place Jussieu, 75252, Paris, France.
Sci Rep. 2024 Sep 27;14(1):22179. doi: 10.1038/s41598-024-67971-1.
One of the main challenges in coral reef conservation and restoration is the identification of coral populations resilient under global warming. Seascape genomics is a powerful tool to uncover genetic markers potentially involved in heat tolerance among large populations without prior information on phenotypes. Here, we aimed to provide first insights on the role of candidate heat associated loci identified using seascape genomics in driving the phenotypic response of Acropora millepora from New Caledonia to thermal stress. We subjected 7 colonies to a long-term ex-situ heat stress assay (4 °C above the maximum monthly mean) and investigated their physiological response along with their Symbiodiniaceae communities and genotypes. Despite sharing similar thermal histories and associated symbionts, these conspecific individuals differed greatly in their tolerance to heat stress. More importantly, the clustering of individuals based on their genotype at heat-associated loci matched the phenotypic variation in heat tolerance. Colonies that sustained on average lower mortality, higher Symbiodiniaceae/chlorophyll concentrations and photosynthetic efficiency under prolonged heat stress were also the closest based on their genotypes, although the low sample size prevented testing loci predictive accuracy. Together these preliminary results support the relevance of coupling seascape genomics and long-term heat stress experiments in the future, to evaluate the effect size of candidate heat associated loci and pave the way for genomic predictive models of corals heat tolerance.
珊瑚礁保护和恢复的主要挑战之一是确定在全球变暖下具有弹性的珊瑚种群。景观基因组学是一种强大的工具，可以在没有表型信息的情况下，揭示可能与耐热性相关的遗传标记，从而对大种群进行研究。在这里，我们旨在提供关于使用景观基因组学识别的候选热相关基因座在驱动来自新喀里多尼亚的石珊瑚对热应激的表型反应中的作用的初步见解。我们将 7 个珊瑚丛置于长期的异位热应激试验（比最高月平均值高 4°C）中，并研究了它们的生理反应以及共生体群落和基因型。尽管这些同种个体具有相似的热历史和相关的共生体，但它们对热应激的耐受性却有很大差异。更重要的是，基于与热相关基因座的基因型对个体进行聚类，与耐热性的表型变异相匹配。在长时间的热应激下，平均死亡率较低、共生体/叶绿素浓度较高且光合作用效率较高的珊瑚丛，其基因型也最接近，尽管样本量低，无法测试预测位点的准确性。这些初步结果共同支持未来将景观基因组学和长期热应激实验相结合的相关性，以评估候选热相关基因座的效应大小，并为珊瑚耐热性的基因组预测模型铺平道路。
