Photoperiodic regulation of puberty in seasonal species
Photoperiodic regulation of puberty in seasonal species
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DOI：
10.1016/j.mce.2010.03.018
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发表时间：
2010-08-05
影响因子：
4.1
通讯作者：
Ebling, Francis J. P.
中科院分区：
文献类型：
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作者：
Ebling, Francis J. P.
在温带或北极地区的大多数哺乳动物中，青春期是季节性发生的，在寿命足够长的物种中，青春期可以被认为每年都会重复发生。青春期的精确时间和生育力的年度重现反映了环境日长(光周期)的变化和内生的长期计时过程的相互作用，在一些物种中，这构成了大约一年的时钟。最近的研究揭示了哺乳动物和鸟类中一种意想不到的光周期信息的共同信号通路：垂体柄中结节的分泌活动的变化，向第三脑室内室管膜中的张力细胞发出信号。松弛细胞中的靶基因编码脱碘酶，该酶调节下丘脑中甲状腺激素的供应。甲状腺激素的中枢可获得性似乎是季节性生殖过渡的关键决定因素。鉴于甲状腺激素对中枢神经系统的初始发育是必要的，假设在青春期和生育的季节性重复发生时，是局部甲状腺激素水平的变化协调下丘脑的可塑性，最终影响GnRH的分泌。(C)2010爱思唯尔爱尔兰有限公司。保留所有权利。
Puberty occurs seasonally in the majority of mammals native to temperate or arctic latitudes, and in species with sufficiently long life spans puberty can be considered to reoccur on an annual basis. The precise timing of puberty and the annual reoccurrence of fertility reflects an interaction of changes in ambient daylength (photoperiod) and endogenous long-term timing processes, which in some species constitute circannual clocks. Recent studies reveal an unexpected common signalling pathway for photoperiodic information in mammals and birds: changes in secretory activity of the pars tuberalis in the pituitary stalk signal to the tanycyte cells in the ependyma lining the third ventricle. The target genes in the tanycytes encode the deiodinase enzymes that regulate the availability of thyroid hormone in the hypothalamus. Central availability of thyroid hormone appears to be the key determinant of seasonal reproductive transitions. Given the necessity of thyroid hormone for the initial development of the central nervous system, it is hypothesized that at puberty and seasonal reoccurrences of fertility it is the changing local levels of thyroid hormone that orchestrate hypothalamic plasticity, ultimately impinging upon the secretion of GnRH. (C) 2010 Elsevier Ireland Ltd. All rights reserved.