An extended family of novel vertebrate photopigments is widely expressed and displays a diversity of function.
An extended family of novel vertebrate photopigments is widely expressed and displays a diversity of function.
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DOI：
10.1101/gr.189886.115
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发表时间：
2015-11
期刊：
影响因子：
7
通讯作者：
Hankins MW
中科院分区：
文献类型：
--
作者：
Davies WI;Tamai TK;Zheng L;Fu JK;Rihel J;Foster RG;Whitmore D;Hankins MW
光对动物生理和行为的影响不仅仅是通过经典的视觉和图像形成途径。非视觉光感受调节许多生物系统，包括昼夜节律夹带，DNA修复，代谢和行为。然而，对于大多数这些过程，涉及的感光分子是未知的。鉴于生物生理反应的多样性，出现了一个问题，是否一个单一的色素或视蛋白超家族内的蛋白质更大的多样性检测光刺激。在这里，功能基因组学的方法确定了一个高度光敏感的模式脊椎动物，斑马鱼（Danio rerio）的色素的完整的补充，并表征其组织分布，表达水平和生化特性。这里呈现的结果揭示了存在42个不同的基因编码10个经典的视觉色素和32个非视觉视蛋白，包括10个新的视蛋白基因，包括四个新的色素类。与斑马鱼中存在的光可降解昼夜节律振荡器一致，所有成年组织检查表达两种或更多种视蛋白，包括几种新的视蛋白。新的视蛋白的光谱和电生理学分析表明，它们形成功能性色素，每个具有独特的发色团结合和波长特异性。这项研究揭示了斑马鱼中色素的数量和多样性，这是迄今为止在任何脊椎动物中发现的最大数量。在两栖动物，爬行动物，鸟类和所有三种哺乳动物分支中发现，这些基因中的大多数并不局限于硬骨鱼。因此，非可见光检测远比最初认识到的复杂，这对理解脊椎动物的光感受具有重要的生物学意义。
Light affects animal physiology and behavior more than simply through classical visual, image-forming pathways. Nonvisual photoreception regulates numerous biological systems, including circadian entrainment, DNA repair, metabolism, and behavior. However, for the majority of these processes, the photoreceptive molecules involved are unknown. Given the diversity of photophysiological responses, the question arises whether a single photopigment or a greater diversity of proteins within the opsin superfamily detect photic stimuli. Here, a functional genomics approach identified the full complement of photopigments in a highly light-sensitive model vertebrate, the zebrafish (Danio rerio), and characterized their tissue distribution, expression levels, and biochemical properties. The results presented here reveal the presence of 42 distinct genes encoding 10 classical visual photopigments and 32 nonvisual opsins, including 10 novel opsin genes comprising four new pigment classes. Consistent with the presence of light-entrainable circadian oscillators in zebrafish, all adult tissues examined expressed two or more opsins, including several novel opsins. Spectral and electrophysiological analyses of the new opsins demonstrate that they form functional photopigments, each with unique chromophore-binding and wavelength specificities. This study has revealed a remarkable number and diversity of photopigments in zebrafish, the largest number so far discovered for any vertebrate. Found in amphibians, reptiles, birds, and all three mammalian clades, most of these genes are not restricted to teleosts. Therefore, nonvisual light detection is far more complex than initially appreciated, which has significant biological implications in understanding photoreception in vertebrates.