Jiang Nan, Wang Zixu, Cao Jing, Dong Yulan, Chen Yaoxing
Laboratory of Anatomy of Domestic Animals, College of Animal Medicine, China Agricultural University, Haidian, Beijing 100193, China.
Laboratory of Anatomy of Domestic Animals, College of Animal Medicine, China Agricultural University, Haidian, Beijing 100193, China.
J Photochem Photobiol B. 2017 Aug;173:476-484. doi: 10.1016/j.jphotobiol.2017.06.027. Epub 2017 Jun 23.
To clarify the effect of monochromatic light on circadian clock gene expression in chick hypothalamus, a total 240 newly hatched chickens were reared under blue light (BL), green light (GL), red light (RL) and white light (WL), respectively. On the post-hatched day 14, 24-h profiles of seven core clock genes (cClock, cBmal1, cBmal2, cCry1, cCry2, cPer2 and cPer3) were measured at six time points (CT 0, CT 4, CT 8, CT 12, CT 16, CT 20, circadian time). We found all these clock genes expressed with a significant rhythmicity in different light wavelength groups. Meanwhile, cClock and cBmal1 showed a high level under GL, and followed a corresponding high expression of cCry1. However, RL decreased the expression levels of these genes. Be consistent with the mRNA level, CLOCK and BMAL1 proteins also showed a high level under GL. The CLOCK-like immunoreactive neurons were observed not only in the SCN, but also in the non-SCN brain region such as the nucleus anterior medialis hypothalami, the periventricularis nucleus, the paraventricular nucleus and the median eminence. All these results are consistent with the auto-regulatory circadian feedback loop, and indicate that GL may play an important role on the circadian time generation and development in the chick hypothalamus. Our results also suggest that the circadian clock in the chick hypothalamus such as non-SCN brain region were involved in the regulation of photo information.
为阐明单色光对雏鸡下丘脑生物钟基因表达的影响，总共240只新孵化的雏鸡分别饲养在蓝光（BL）、绿光（GL）、红光（RL）和白光（WL）下。在孵化后第14天，在六个时间点（昼夜时间CT 0、CT 4、CT 8、CT 12、CT 16、CT 20）测量七个核心生物钟基因（cClock、cBmal1、cBmal2、cCry1、cCry2、cPer2和cPer3）的24小时表达谱。我们发现所有这些生物钟基因在不同光波长组中均有显著的节律性表达。同时，cClock和cBmal1在绿光下表达水平较高，且cCry1相应地高表达。然而，红光降低了这些基因的表达水平。与mRNA水平一致，CLOCK和BMAL1蛋白在绿光下也呈现高表达。不仅在视交叉上核（SCN），而且在非SCN脑区如内侧下丘脑前核、室周核、室旁核和正中隆起中均观察到CLOCK样免疫反应性神经元。所有这些结果与自动调节的昼夜反馈环一致，表明绿光可能在雏鸡下丘脑昼夜节律的产生和发展中起重要作用。我们的结果还表明，雏鸡下丘脑如非SCN脑区的生物钟参与了光信息的调节。
