Environmentally regulated genes as basis for coral reef resilience

环境调节基因作为珊瑚礁恢复力的基础

• 批准号: NE/I01683X/1
• 负责人: Joerg Wiedenmann
• 金额: $ 4.57万
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2011
• 资助国家: 英国
• 起止时间: 2011 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FI01683X%2F1
• 关键词: Environmentally; regulated; genes; basis; coral

Tropical coral reefs are among the most important centres of marine biodiversity, providing invaluable ecosystem services as millions of people are economically dependent on the reef and its creatures. A multiplicity of natural and anthropogenic stressors such as global warming and ocean acidification might result in a dramatic loss of coral reefs within this century. Increasing stress for marine organisms is expected in response to the anthropogenic increase in CO2, especially to rising seawater temperatures and decreasing pH. The future of coral reefs is strongly dependent on the capability of scleractinian corals to adapt to these changes in environmental conditions. Their adaptation potential is defined by their capacity to evolve new traits or to regulate the expression of existing genes. However, current climate change happens over an unprecedented short period of time, preventing an adaptation of reef corals by evolution of new traits. Consequently, their main strategy for survival may lie in the phenotypic plasticity that is already encoded in their genome. Up-regulation of certain genes in response to changing environmental conditions, for instance, can be realized on the level of the individual gene or on the population level by the positive selection of genotypes which show increased expression levels. Individuals with deviating expression levels can be present in a population as result of preadaptation processes and / or by positive selection in certain ecological niches with extreme environmental conditions. Hence, predictability of the future of reef-building corals depends strongly on knowledge of the functioning of environmentally regulated genes, an aspect as yet largely unstudied. Therefore, we set out to explore the genomic basis of environmentally controlled genes in hermatypic corals. We identified the coral Acropora millepora and its gene encoding the red fluorescent protein amFP597 (RFP) as ideal model system to study the regulatory plasticity of environmentally controlled genes. The RFP is considered to fulfill a photoprotective function, optimizing growth in shallow waters. We found that the RFP-encoding gene is strongly up-regulated by light. It shows the same response to changes in the light climate in different colour morphs of A. millepora. However, we determined strong differences between the morphs regarding the absolute amount of transcripts: The RFP transcript concentration was, for instance, more than five-fold higher both in the light exposed and shaded tissue in the red morph compared to the green morph. These results imply that the tissue concentration of a protective coral protein depends not only on the environmental control of the encoding gene but also on the morphotype-specific maximal response of the gene to a stimulus. The variability in transcript levels among the colour morphs appears to be genetically fixed as colour differences within species are retained under identical environmental conditions. Therefore, this striking case of regulatory plasticity offers ideal conditions to study the genomic basis of environmentally regulated genes. We will evaluate two genetic scenarios most likely to explain the observed differences in the RFP transcript levels: A) The colour morphs possess different variants of the RFP-encoding gene with altered sequences, for instance, in the gene regulatory region (promoter). B) The RFP-encoding gene is present in different copy numbers among the colour morphs. To address the question which scenario is realised in A. millepora, we will perform an in-depth analysis of the RFP-encoding gene in the green, brown and red colour morphs. The required corals are already kept and propagated in the experimental aquarium system of the Coral Laboratory at NOCS. We will apply a suite of advanced molecular biological techniques to gain unprecedented insights in gene regulation strategies in reef corals.

热带珊瑚礁是海洋生物多样性中最重要的中心之一，随着数百万人在经济上依赖礁石及其生物而提供了宝贵的生态系统服务。多种自然和人为应激源（例如全球变暖和海洋酸化）可能会导致本世纪内珊瑚礁的巨大丧失。预计海洋生物的压力增加会随着二氧化碳的人为增加的响应，尤其是海水温度升高和pH值降低。珊瑚礁的未来在很大程度上取决于巩膜珊瑚的能力，适应环境条件上的这些变化。它们的适应潜力是由它们发展新特征或调节现有基因表达的能力来定义的。但是，当前的气候变化发生在空前的短时间内，从而防止了新特征的进化来适应珊瑚礁珊瑚。因此，它们的生存主要策略可能在于已经在其基因组中编码的表型可塑性。例如，可以通过在单个基因的水平或种群水平上实现某些基因对某些基因的上调，这表明基因型的阳性选择显示出表达水平的增加。由于前环境条件的某些生态壁ches，在人群中可能存在偏差表达水平的个体。因此，珊瑚礁珊瑚的未来的可预测性在很大程度上取决于对环境调节基因功能的知识，这一方面尚未被研究。因此，我们着手探索雌雄同体珊瑚中环境控制基因的基因组基础。我们确定了珊瑚Acropora millepora及其编码红色荧光蛋白AMFP597（RFP）的基因是研究环境控制基因的调节可塑性的理想模型系统。 RFP被认为可以实现光保护功能，从而优化了浅水的生长。我们发现，RFP编码基因被光强烈上调。它显示出对A. millepora不同颜色变化的光气候变化的反应。但是，我们确定了在转录本的绝对量中的形态之间的强烈差异：例如，与绿色变体相比，在红色变体的光和阴影组织中，RFP转录浓度在五倍以上。这些结果表明，保护性珊瑚蛋白的组织浓度不仅取决于编码基因的环境控制，还取决于该基因对刺激的形态型特异性最大反应。颜色形态之间转录水平的变异似乎是遗传固定的，因为在相同的环境条件下物种中的颜色差异保留。因此，这种调节可塑性的惊人案例提供了研究环境调节基因的基因组基础的理想条件。我们将评估两个遗传情景最有可能解释RFP转录水平上观察到的差异：a）颜色变体具有不同序列的RFP编码基因的不同变体，例如，在基因调节区域（启动子）中。 b）RFP编码基因在颜色形态之间存在不同的拷贝数。为了解决A. Millepora中哪种情况的问题，我们将对绿色，棕色和红色变形的RFP编码基因进行深入分析。所需的珊瑚已经在NOC的珊瑚实验室的实验水族馆系统中保存并传播。我们将应用一组晚期分子生物学技术来获得珊瑚礁珊瑚基因调节策略的前所未有的见解。

项目成果

Corals display bright colours to fight bleaching

珊瑚呈现出鲜艳的颜色以对抗白化

• DOI: 10.25250/thescbr.brk429
• 发表时间: 2020
• 期刊: TheScienceBreaker
• 作者: Bollati E

Locally accelerated growth is part of the innate immune response and repair mechanisms in reef-building corals as detected by green fluorescent protein (GFP)-like pigments

• DOI: 10.1007/s00338-012-0926-8
• 发表时间: 2012-12-01
• 期刊: CORAL REEFS
• 影响因子: 3.5
• 作者: D'Angelo, C.;Smith, E. G.;Wiedenmann, J.
• 通讯作者: Wiedenmann, J.

Spectral Diversity and Regulation of Coral Fluorescence in a Mesophotic Reef Habitat in the Red Sea.

• DOI: 10.1371/journal.pone.0128697
• 发表时间: 2015
• 期刊: PloS one
• 影响因子: 3.7
• 作者: Eyal G;Wiedenmann J;Grinblat M;D'Angelo C;Kramarsky-Winter E;Treibitz T;Ben-Zvi O;Shaked Y;Smith TB;Harii S;Denis V;Noyes T;Tamir R;Loya Y
• 通讯作者: Loya Y

FRET-Mediated Long-Range Wavelength Transformation by Photoconvertible Fluorescent Proteins as an Efficient Mechanism to Generate Orange-Red Light in Symbiotic Deep Water Corals.

• DOI: 10.3390/ijms18071174
• 发表时间: 2017-07-04
• 期刊: International journal of molecular sciences
• 影响因子: 5.6
• 作者: Bollati E;Plimmer D;D'Angelo C;Wiedenmann J
• 通讯作者: Wiedenmann J

Fluorescent protein-mediated colour polymorphism in reef corals: multicopy genes extend the adaptation/acclimatization potential to variable light environments.

• DOI: 10.1111/mec.13041
• 发表时间: 2015-01
• 期刊: Molecular ecology
• 影响因子: 4.9
• 作者: Gittins JR;D'Angelo C;Oswald F;Edwards RJ;Wiedenmann J
• 通讯作者: Wiedenmann J