Fluorescent protein-mediated colour polymorphism in reef corals: multicopy genes extend the adaptation/acclimatization potential to variable light environments.
Fluorescent protein-mediated colour polymorphism in reef corals: multicopy genes extend the adaptation/acclimatization potential to variable light environments.
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DOI：
10.1111/mec.13041
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发表时间：
2015-01
影响因子：
4.9
通讯作者：
Wiedenmann J
中科院分区：
文献类型：
--
作者：
Gittins JR;D'Angelo C;Oswald F;Edwards RJ;Wiedenmann J
使珊瑚能够适应不利条件的基因组框架对于珊瑚礁在快速变化的气候中的生存至关重要。我们已经探讨了显着的种内变异的珊瑚色素的表达从绿色荧光蛋白（GFP）家庭，阐明的基因组基础的可塑性的压力反应之间的珊瑚礁。我们发现，多拷贝基因可以大大增加动态范围，珊瑚可以调节转录水平，以响应光环境。使用红色荧光蛋白amilFP597在珊瑚鹿角珊瑚作为一个模型，我们表明，它的表达随着光强度的增加，但最小和最大的基因转录水平显着不同的颜色形态。不同形态组织中的色素浓度与特定启动子类型的基因拷贝数密切相关。这些发现表明，珊瑚礁的颜色多态性可能是由环境调节的多拷贝基因表达引起的。amilFP597的高水平表达与急性光胁迫下虫黄色素的光损伤减少相关，支持该色素的光保护功能。光调节色素基因簇可以使珊瑚投资于昂贵的高水平色素沉着，在光压力下提供益处，或者依赖于低组织色素浓度并将保存的资源用于其他目的，这在光照较少的环境中是优选的。这里描述的基因组框架允许珊瑚追求不同的策略，以在具有高度可变的光应力水平的栖息地中取得成功。总之，我们的研究结果表明，种内可塑性的礁珊瑚的压力反应比以前认为的更大。
The genomic framework that enables corals to adjust to unfavourable conditions is crucial for coral reef survival in a rapidly changing climate. We have explored the striking intraspecific variability in the expression of coral pigments from the green fluorescent protein (GFP) family to elucidate the genomic basis for the plasticity of stress responses among reef corals. We show that multicopy genes can greatly increase the dynamic range over which corals can modulate transcript levels in response to the light environment. Using the red fluorescent protein amilFP597 in the coral Acropora millepora as a model, we demonstrate that its expression increases with light intensity, but both the minimal and maximal gene transcript levels vary markedly among colour morphs. The pigment concentration in the tissue of different morphs is strongly correlated with the number of gene copies with a particular promoter type. These findings indicate that colour polymorphism in reef corals can be caused by the environmentally regulated expression of multicopy genes. High‐level expression of amilFP597 is correlated with reduced photodamage of zooxanthellae under acute light stress, supporting a photoprotective function of this pigment. The cluster of light‐regulated pigment genes can enable corals to invest either in expensive high‐level pigmentation, offering benefits under light stress, or to rely on low tissue pigment concentrations and use the conserved resources for other purposes, which is preferable in less light‐exposed environments. The genomic framework described here allows corals to pursue different strategies to succeed in habitats with highly variable light stress levels. In summary, our results suggest that the intraspecific plasticity of reef corals’ stress responses is larger than previously thought.