Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; email:
Laboratory of Animal Integrative Physiology, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
Annu Rev Anim Biosci. 2019 Feb 15;7:173-194. doi: 10.1146/annurev-animal-020518-115216. Epub 2018 Oct 17.
Organisms use changes in photoperiod for seasonal reproduction to maximize the survival of their offspring. Birds have sophisticated seasonal mechanisms and are therefore excellent models for studying these phenomena. Birds perceive light via deep-brain photoreceptors and long day-induced thyroid-stimulating hormone (TSH, thyrotropin) in the pars tuberalis of the pituitary gland (PT), which cause local thyroid hormone activation within the mediobasal hypothalamus. The local bioactive thyroid hormone controls seasonal gonadotropin-releasing hormone secretion and subsequent gonadotropin secretion. In mammals, the eyes are believed to be the only photoreceptor organ, and nocturnal melatonin secretion triggers an endocrine signal that communicates information about the photoperiod to the PT to regulate TSH. In contrast, in Salmonidae fish the input pathway to the neuroendocrine output pathway appears to be localized in the saccus vasculosus. Thus, comparative analysis is an effective way to uncover the universality and diversity of fundamental traits in various organisms.
生物利用光周期变化进行季节性繁殖，以使后代的生存最大化。鸟类具有复杂的季节性机制，因此是研究这些现象的绝佳模型。鸟类通过深部脑光感受器感知光线，而长日照诱导的垂体中叶管促甲状腺激素（TSH，促甲状腺素）会引起垂体中叶管（PT）中的局部甲状腺激素激活，从而导致中脑基底部的局部生物活性甲状腺激素控制季节性促性腺激素释放激素的分泌和随后的促性腺激素的分泌。在哺乳动物中，眼睛被认为是唯一的光感受器器官，而夜间褪黑素的分泌会引发内分泌信号，将关于光周期的信息传递给 PT 以调节 TSH。相比之下，在鲑科鱼类中，神经内分泌输出途径的输入途径似乎定位于血管球囊。因此，比较分析是揭示各种生物体中基本特征的普遍性和多样性的有效方法。
