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最重要的中心之一，提供了宝贵的生态系统服务，因为数百万人在经济上依赖于珊瑚礁及其生物。全球变暖和海洋酸化等多种自然和人为压力可能会在本世纪内导致珊瑚礁的急剧丧失。预计海洋生物面临的压力将会增加，以应对二氧化碳的人为增加，特别是海水温度的上升和pH的下降。珊瑚礁的未来在很大程度上取决于珊瑚适应这些环境条件变化的能力。它们的适应潜力是由它们进化新特征或调节现有基因表达的能力来定义的。然而，当前的气候变化发生在前所未有的短时间内，阻止了珊瑚礁通过新特征的进化来适应。因此，它们的主要生存策略可能在于它们基因组中已经编码的表型可塑性。例如，某些基因对环境条件变化的反应上调，可以在个体基因水平上实现，也可以在群体水平上通过对表现出表达水平增加的基因型的积极选择来实现。由于预适应过程和/或在极端环境条件下的某些生态位中的正向选择，表达水平不同的个体可能出现在种群中。因此，造礁珊瑚的未来的可预测性在很大程度上取决于对环境调控基因功能的了解，这一方面迄今基本上还没有研究过。因此，我们着手探索环境控制的基因在珊瑚中的基因组基础。我们确定珊瑚多孔菌及其编码红色荧光蛋白amFP597(RFP)的基因是研究环境控制基因调控可塑性的理想模式系统。RFP被认为具有光保护功能，优化了浅水中的生长。我们发现，编码RFP的基因在光的作用下被强烈上调。不同颜色变型的黄曲霉对光气候变化的反应是一致的。然而，我们发现在转录物的绝对数量上，不同的变形体之间存在很大的差异：例如，与绿色变形体相比，红色变形体在光照和阴影下的RFP转录本浓度都要高出五倍以上。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特异性最大反应。由于物种间的颜色差异在相同的环境条件下保持不变，不同颜色变体之间转录水平的差异似乎是遗传固定的。因此，这一显著的调控可塑性案例为研究环境调控基因的基因组基础提供了理想的条件。我们将评估两种最有可能解释所观察到的RFP转录水平差异的遗传情景：a)颜色变体具有不同的RFP编码基因变体，具有改变的序列，例如，在基因调节区(启动子)。B)编码RFP的基因在不同的颜色变体中以不同的拷贝数存在。为了解决在白粉菌中实现哪种情况的问题，我们将对绿色、棕色和红色变种中的RFP编码基因进行深入分析。所需的珊瑚已经保存在国家海洋科学中心珊瑚实验室的实验水族馆系统中并进行繁殖。我们将应用一套先进的分子生物学技术，以获得对珊瑚礁基因调控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.

红色海洋中生礁栖息地中珊瑚荧光的光谱多样性和调节。

• 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

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

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