Jules Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-7000, USA.
Jules Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-7000, USA; Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA 90095-7000, USA.
Curr Biol. 2021 Jan 25;31(2):R65-R66. doi: 10.1016/j.cub.2020.11.021.
The discoveries of the photopigment melanopsin and intrinsically photosensitive retinal ganglion cells (ipRGCs) have revealed novel mechanisms of light detection now known to control several kinds of non-image-forming vision, including regulation of mood, the circadian rhythm, and the pupillary light reflex (PLR). These remarkable discoveries have been made mostly on mammals, but many vertebrates express melanopsin and adjust the diameter of the pupil to the ambient light intensity to extend the operating range of vision and reduce spherical aberration. We were curious to know whether a PLR controlled by melanopsin is also present in lamprey, which are members of the only remaining group of jawless vertebrates (agnathans) which diverged from all other vertebrates about 500 million years ago. We now show that lamprey have a robust PLR mediated by melanopsin apparently without any contribution from signals of rods and cones, suggesting that non-image-forming perception emerged long before the radiation of present vertebrate lines and was already present in the late Cambrian.
感光色素黑视蛋白和内在光敏视网膜神经节细胞(ipRGCs)的发现揭示了新的光检测机制，这些机制现在被认为可以控制多种非成像视觉，包括调节情绪、昼夜节律和瞳孔光反射(PLR)。这些非凡的发现主要是在哺乳动物身上做出的，但许多脊椎动物都表达黑视蛋白，并调整瞳孔直径以适应环境光强度，从而扩展视觉的工作范围并减少球差。我们很好奇，是否在七鳃鳗中也存在由黑视蛋白控制的 PLR，七鳃鳗是无颌脊椎动物(无颌类)中唯一现存的群体，它们大约在 5 亿年前与所有其他脊椎动物分离。我们现在表明，七鳃鳗具有由黑视蛋白介导的强大的 PLR，显然没有来自视杆细胞和视锥细胞信号的任何贡献，这表明非成像感知在现今脊椎动物谱系辐射之前很久就出现了，并且已经存在于晚寒武纪。
