Data from: Plasticity contributes to a fine-scale depth gradient in sticklebacks’ visual system

The light environment influences an animal’s ability to forage, evade predators, and find mates, and consequently is known to drive local adaptation of visual systems. However, the light environment may also vary over fine spatial scales at which genetic adaptation is difficult. For instance, in aquatic systems the available wavelengths of light change over a few meters depth. Do animals plastically adjust their visual system to such small-scale environmental light variation? Here, we show that in threespine stickleback (Gasterosteus aculeatus), opsin gene expression (an important determinant of colour vision) changes over a 2-meter vertical gradient in nest depth. By experimentally altering the light environment using light filters to cover enclosures in a lake, we found that opsin expression can be adjusted on a short time frame (weeks) in response to the local light environment. This is to our knowledge the smallest spatial scale on which visual adjustments through opsin expression have been recorded in a natural setting along a continuously changing light environment.光照环境会影响动物的觅食、避敌与求偶能力，已知其可驱动视觉系统的局部适应。然而，光照环境也可能在精细空间尺度上发生变化，而此类尺度下的遗传适应往往难以实现。例如，在水生生态系统中，可利用的光波长会随数米深度的变化而改变。那么，动物是否会通过表型可塑性调整其视觉系统，以应对这类小尺度的环境光变异？本研究以三刺鱼（Gasterosteus aculeatus）为对象，结果显示其视蛋白基因表达——这是决定色觉的关键因素之一——会随巢深2米的垂直梯度发生改变。通过在湖泊围隔中加装滤光装置以实验性调控光照环境，我们发现视蛋白基因表达可在短期（数周）内响应局部光照环境发生调整。据我们所知，这是在自然环境中，沿连续变化的光环境梯度所记录到的、通过视蛋白基因表达实现视觉调整的最小空间尺度。