A mammalian neural tissue opsin (Opsin 5) is a deep brain photoreceptor in birds
A mammalian neural tissue opsin (Opsin 5) is a deep brain photoreceptor in birds
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DOI：
10.1073/pnas.1006393107
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发表时间：
2010-08-24
影响因子：
11.1
通讯作者：
Yoshimura, Takashi
中科院分区：
文献类型：
--
作者：
Nakane, Yusuke;Ikegami, Keisuke;Yoshimura, Takashi
几十年来，人们已经知道，非哺乳类脊椎动物通过位于视网膜和松果体器官外部的脑深部光感受器来检测光，以调节生殖的季节性周期。然而，这些光感受器的身份至今仍不清楚。在这里，我们报告说，视蛋白5是在鹌鹑脑深部脑光感受分子。视蛋白超家族成员在室旁器官（PVO）中的表达分析，视蛋白超家族成员被鉴定为视蛋白5（OPN 5;也称为Gpr 136、Neuropsin、PGR 12和TMEM 13）mRNA，PVO是一个长期被认为能够进行光转导的区域。免疫组织化学鉴定了PVO中接触脑脊液的神经元中的视蛋白5，以及延伸到垂体结节部附近的正中隆起的外部区域的纤维，其将光周期信息转化为神经内分泌反应。视蛋白5在非洲爪蟾卵母细胞中的异源表达导致膜电流的光依赖性激活，其作用光谱在类似于420 nm处显示峰值灵敏度（λ（max））。我们还发现，短波长光，即，在UV-B和蓝光之间，诱导了眼罩，松果体切除鹌鹑的光周期反应。因此，视蛋白5似乎是调节鸟类季节性繁殖的脑深部光感受分子之一。
It has been known for many decades that nonmammalian vertebrates detect light by deep brain photoreceptors that lie outside the retina and pineal organ to regulate seasonal cycle of reproduction. However, the identity of these photoreceptors has so far remained unclear. Here we report that Opsin 5 is a deep brain photoreceptive molecule in the quail brain. Expression analysis of members of the opsin superfamily identified as Opsin 5 (OPN5; also known as Gpr136, Neuropsin, PGR12, and TMEM13) mRNA in the paraventricular organ (PVO), an area long believed to be capable of photo-transduction. Immunohistochemistry identified Opsin 5 in neurons that contact the cerebrospinal fluid in the PVO, as well as fibers extending to the external zone of the median eminence adjacent to the pars tuberalis of the pituitary gland, which translates photoperiodic information into neuroendocrine responses. Heterologous expression of Opsin 5 in Xenopus oocytes resulted in light-dependent activation of membrane currents, the action spectrum of which showed peak sensitivity (lambda(max)) at similar to 420 nm. We also found that short-wavelength light, i.e., between UV-B and blue light, induced photoperiodic responses in eye-patched, pinealectomized quail. Thus, Opsin 5 appears to be one of the deep brain photoreceptive molecules that regulates seasonal reproduction in birds.