Savelli Ilaria, Novales Flamarique Iñigo
Department of Biological Sciences,Simon Fraser University,Burnaby,British Columbia V5A 1S6,Canada.
Vis Neurosci. 2018 Jan;35:E005. doi: 10.1017/S0952523818000019.
Vertebrate retinal photoreceptors house visual pigments that absorb light to begin the process of vision. The light absorbed by a visual pigment depends on its two molecular components: protein (opsin) and chromophore (a vitamin A derivative). Although an increasing number of studies show intraretinal variability in visual pigment content, it is only for two mammals (human and mouse) and two birds (chicken and pigeon) that such variability has been demonstrated to underlie differences in spectral sensitivity of the animal. Here, we show that the spectral sensitivity of the northern anchovy varies with retinal quadrant and that this variability can be explained by differences in the expression of opsin transcripts. Retinal (vitamin A1) was the only chromophore detected in the retina, ruling out this molecular component as a source of variation in spectral sensitivity. Chromatic adaptation experiments further showed that the dorsal retina had the capacity to mediate color vision. Together with published results for the ventral retina, this study is the first to demonstrate that intraretinal opsin variability in a fish drives corresponding variation in the animal's spectral sensitivity.
脊椎动物的视网膜光感受器含有视觉色素，这些色素吸收光线以启动视觉过程。视觉色素吸收的光取决于其两个分子成分：蛋白质（视蛋白）和发色团（一种维生素A衍生物）。尽管越来越多的研究表明视网膜内视觉色素含量存在变异性，但只有两种哺乳动物（人类和小鼠）以及两种鸟类（鸡和鸽子）的这种变异性被证明是动物光谱敏感性差异的基础。在这里，我们表明北鳀的光谱敏感性随视网膜象限而变化，并且这种变异性可以通过视蛋白转录本表达的差异来解释。视网膜（维生素A1）是在视网膜中检测到的唯一发色团，排除了这种分子成分作为光谱敏感性变化来源的可能性。色适应实验进一步表明，背侧视网膜具有介导色觉的能力。结合已发表的关于腹侧视网膜的结果，本研究首次证明鱼类视网膜内视蛋白的变异性驱动了动物光谱敏感性的相应变化。
