Foster R G, Follett B K, Lythgoe J N
Nature. 1985;313(5997):50-2. doi: 10.1038/313050a0.
It has been known for some 50 years that birds use photoreceptors in or near the hypothalamus to mediate the photoperiodic responses that control seasonal breeding. So far, however, attempts to identify the photopigment by determining an action spectrum have failed. The problems stem from the selective filtering of light by the tissues surrounding the photoreceptors and the need to deliver defined amounts of light over the days or weeks required to induce a quantitative measure of photostimulation. Here we have developed a technique which produces a quantitative action spectrum for the photoperiodic response in the Japanese quail; the results indicate the presence of a rhodopsin photopigment with a peak sensitivity of approximately 492 nm. The photoreceptors exhibit a level of sensitivity comparable with that of vertebrate visual pigments. We conclude that the brain photoreceptors of birds are based on a rhodopsin/rhodopsin-like photopigment.
大约50年前人们就知道，鸟类利用下丘脑内或其附近的光感受器来介导控制季节性繁殖的光周期反应。然而，迄今为止，通过确定作用光谱来识别光色素的尝试均以失败告终。问题源于光感受器周围组织对光的选择性过滤，以及需要在诱导光刺激定量测量所需的数天或数周时间内提供确定量的光。在此，我们开发了一种技术，可产生日本鹌鹑光周期反应的定量作用光谱；结果表明存在一种视紫红质光色素，其峰值灵敏度约为492纳米。这些光感受器表现出与脊椎动物视觉色素相当的灵敏度水平。我们得出结论，鸟类的脑光感受器是基于视紫红质/类视紫红质光色素。
