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

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 multi-copy 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 ...

在气候快速变化的背景下，助力珊瑚适应逆境的基因组调控框架，是珊瑚礁得以存续的关键所在。本研究针对珊瑚来源的绿色荧光蛋白（green fluorescent protein, GFP）家族色素的显著种内表达差异展开探究，以期阐明造礁珊瑚应激响应可塑性的基因组基础。研究表明，多拷贝基因可大幅拓宽珊瑚响应光照环境时的转录水平调控动态范围。本研究以多孔鹿角珊瑚（Acropora millepora）中的红色荧光蛋白amilFP597为模型，证实其表达量随光照强度升高而上升，但不同颜色形态个体的基因转录最低水平与最高水平均存在显著差异。不同形态个体的组织内色素浓度，与携带特定启动子类型的基因拷贝数呈显著正相关。上述研究结果表明，造礁珊瑚的颜色多态性可能由……引发