Sakai Yusuke, Ohtsuki Hajime, Kasagi Satoshi, Kawamura Shoji, Kawata Masakado
Department of Ecology and Evolutionary Biology, Graduate School of Life Sciences, Tohoku University, 980-8578, Sendai, Japan.
Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, 277-8562, Kashiwa, Japan.
BMC Evol Biol. 2016 May 18;16(1):106. doi: 10.1186/s12862-016-0679-z.
The visual system is important for animals for mate choice, food acquisition, and predator avoidance. Animals possessing a visual system can sense particular wavelengths of light emanating from objects and their surroundings and perceive their environments by processing information contained in these visual perceptions of light. Visual perception in individuals varies with the absorption spectra of visual pigments and the expression levels of opsin genes, which may be altered according to the light environments. However, which light environments and the mechanism by which they change opsin expression profiles and whether these changes in opsin gene expression can affect light sensitivities are largely unknown. This study determined whether the light environment during growth induced plastic changes in opsin gene expression and behavioral sensitivity to particular wavelengths of light in guppies (Poecilia reticulata).
Individuals grown under orange light exhibited a higher expression of long wavelength-sensitive (LWS) opsin genes and a higher sensitivity to 600-nm light than those grown under green light. In addition, we confirmed that variations in the expression levels of LWS opsin genes were related to the behavioral sensitivities to long wavelengths of light.
The light environment during the growth stage alters the expression levels of LWS opsin genes and behavioral sensitivities to long wavelengths of light in guppies. The plastically enhanced sensitivity to background light due to changes in opsin gene expression can enhance the detection and visibility of predators and foods, thereby affecting survival. Moreover, changes in sensitivities to orange light may lead to changes in the discrimination of orange/red colors of male guppies and might alter female preferences for male color patterns.
视觉系统对动物进行配偶选择、获取食物和躲避捕食者至关重要。拥有视觉系统的动物能够感知物体及其周围环境发出的特定波长的光，并通过处理这些光视觉感知中包含的信息来感知其环境。个体的视觉感知会因视觉色素的吸收光谱和视蛋白基因的表达水平而有所不同，而这些可能会根据光照环境发生改变。然而，何种光照环境以及它们改变视蛋白表达谱的机制，以及视蛋白基因表达的这些变化是否会影响光敏感度，在很大程度上尚不清楚。本研究确定了孔雀鱼（Poecilia reticulata）生长期间的光照环境是否会诱导视蛋白基因表达的可塑性变化以及对特定波长光的行为敏感性。
在橙色光下生长的个体比在绿色光下生长的个体表现出更高的长波长敏感（LWS）视蛋白基因表达水平，并且对600纳米光的敏感度更高。此外，我们证实LWS视蛋白基因表达水平的变化与对长波长光的行为敏感性相关。
生长阶段的光照环境会改变孔雀鱼中LWS视蛋白基因的表达水平以及对长波长光的行为敏感性。由于视蛋白基因表达的变化而对视背景光的可塑性增强的敏感性可以提高对捕食者和食物的检测和可见性，从而影响生存。此外，对橙色光敏感度的变化可能会导致雄性孔雀鱼对橙色/红色的辨别发生变化，并可能改变雌性对雄性颜色模式的偏好。
