Light-induced body color change in developing zebrafish
Light-induced body color change in developing zebrafish
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DOI：
10.1039/c0pp00199f
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发表时间：
2010-01-01
影响因子：
3.1
通讯作者：
Fukada, Yoshitaka
中科院分区：
文献类型：
--
作者：
Shiraki, Tomoya;Kojima, Daisuke;Fukada, Yoshitaka
许多低等脊椎动物通过调节黑素细胞中黑色素颗粒（黑素体）的分散或聚集，分别对环境光水平作出反应，使它们的身体颜色变暗或变亮。这种生理反应是由眼睛、松果体、深部脑和黑素细胞本身的光接收介导的，这取决于物种和它们的发育阶段。在本研究中，我们建立了一种定量测量光诱导斑马鱼幼虫体色变化的方法。从受精后2天开始，皮肤黑色素细胞对光照有响应，但响应模式和时间分布在不同发育阶段发生变化。在2 dpf时，光照诱导了色素在黑色素细胞中相对较快的分散，而在3 dpf或后期，持续光照导致色素聚集延迟。眼睛的切除消除了依赖光的色素聚集，但没有消除5 dpf处的色素分散，而2 dpf处的色素分散即使在离体尾部也保留了下来。这些结果表明，色素的分散是由黑色素细胞固有的光接受触发的，而色素的聚集是由眼睛的光接受介导的。本研究开发的监测系统将有助于了解眼系统色觉变化的神经机制。我们还讨论了视蛋白型感光分子在光诱导斑马鱼幼鱼体色变化中的可能作用。
In response to ambient light levels, many lower vertebrates darken or lighten their body colors by regulating dispersion or aggregation, respectively, of melanin granules (melanosomes) in the melanophore. This physiological reaction is mediated by photoreception in the eyes, the pineal gland, the deep brain and the melanophores themselves, depending on species and their developmental stages. In this study, we established a method for quantitative measurement of the light-induced body color change in zebrafish larvae. From 2 days post-fertilization (dpf), the dermal melanophores responded to light illumination, but the response patterns and temporal profiles changed across the developmental stages. At 2 dpf, light illumination on larvae induced a relatively fast dispersion of the pigments in the melanophores, whereas continuous illumination additionally caused a delayed pigment aggregation at 3 dpf or later stages. Removal of the eyes abolished the light-dependent pigment aggregation but not the pigment dispersion at 5 dpf, while the pigment dispersion at 2 dpf was retained even in the isolated tail. These results suggest that the pigment dispersion is triggered by photoreception intrinsic to the melanophores and that the pigment aggregation is mediated by photoreception in the eyes. The monitoring system developed in this study will be useful to understand the neural mechanisms underlying the body color change depending on the ocular system. We also discussed the putative role(s) of opsin-type photoreceptive molecules in the light-induced body color change of the larval zebrafish.