Data from: Genomic basis for coral resilience to climate change

Recent advances in DNA-sequencing technologies now allow for in-depth characterization of the genomic stress responses of many organisms beyond model taxa. They are especially appropriate for organisms such as reef-building corals, for which dramatic declines in abundance are expected to worsen as anthropogenic climate change intensifies. Different corals differ substantially in physiological resilience to environmental stress, but the molecular mechanisms behind enhanced coral resilience remain unclear. Here, we compare transcriptome-wide gene expression (via RNA-Seq using Illumina sequencing) among conspecific thermally sensitive and thermally resilient corals to identify the molecular pathways contributing to coral resilience. Under simulated bleaching stress, sensitive and resilient corals change expression of hundreds of genes, but the resilient corals had higher expression under control conditions across 60 of these genes. These “frontloaded” transcripts were less up-regulated in resilient corals during heat stress and included thermal tolerance genes such as heat shock proteins and antioxidant enzymes, as well as a broad array of genes involved in apoptosis regulation, tumor suppression, innate immune response, and cell adhesion. We propose that constitutive frontloading enables an individual to maintain physiological resilience during frequently encountered environmental stress, an idea that has strong parallels in model systems such as yeast. Our study provides broad insight into the fundamental cellular processes responsible for enhanced stress tolerances that may enable some organisms to better persist into the future in an era of global climate change.近年来，DNA测序（DNA-sequencing）技术的最新进展，使得我们能够对非模式类群（model taxa）的多种生物体的基因组应激反应进行深入表征。该类技术尤其适用于造礁珊瑚（reef-building corals）：随着人为气候变化（anthropogenic climate change）加剧，其种群丰度预计将大幅下滑，生存状况愈发严峻。不同珊瑚对环境胁迫的生理耐受性差异显著，但赋予珊瑚增强耐热性的分子机制仍未阐明。本研究通过采用Illumina测序技术的RNA测序（RNA-Seq），对比分析同种热敏感与耐热珊瑚的全转录组基因表达水平，以筛选出与珊瑚耐热性相关的分子通路。在模拟白化胁迫（bleaching stress）环境下，热敏感与耐热珊瑚均有数百个基因的表达发生改变，但耐热珊瑚在正常对照条件下，已有60个这类基因的表达水平更高。这些“前置加载（frontloaded）”的转录本，在热胁迫过程中于耐热珊瑚体内的上调幅度更低，其中包含热休克蛋白（heat shock proteins）、抗氧化酶（antioxidant enzymes）等耐热相关基因，同时还涵盖了大量参与细胞凋亡调控（apoptosis regulation）、肿瘤抑制（tumor suppression）、先天免疫应答（innate immune response）以及细胞黏附（cell adhesion）的基因。我们提出，组成型前置表达（constitutive frontloading）可使生物体在频繁遭遇环境胁迫时维持生理耐受性，这一假说在酵母等模式生物系统中已有充分佐证。本研究为阐释介导增强胁迫耐受性的核心细胞过程提供了广阔视角，而这类耐受性或能帮助部分生物体在全球气候变化时代更好地存续下去。