Shigeyoshi Y, Taguchi K, Yamamoto S, Takekida S, Yan L, Tei H, Moriya T, Shibata S, Loros J J, Dunlap J C, Okamura H
Department of Anatomy and Brain Science, Kobe University School of Medicine, Japan.
Cell. 1997 Dec 26;91(7):1043-53. doi: 10.1016/s0092-8674(00)80494-8.
To understand how light might entrain a mammalian circadian clock, we examined the effects of light on mPer1, a sequence homolog of Drosophila per, that exhibits robust rhythmic expression in the SCN. mPer1 is rapidly induced by short duration exposure to light at levels sufficient to reset the clock, and dose-response curves reveal that mPer1 induction shows both reciprocity and a strong correlation with phase shifting of the overt rhythm. Thus, in both the phasing of dark expression and the response to light mPer1 is most similar to the Neurospora clock gene frq. Within the SCN there appears to be localization of the induction phenomenon, consistent with the localization of both light-sensitive and light-insensitive oscillators in this circadian center.
为了解光照如何调节哺乳动物的生物钟，我们研究了光照对mPer1的影响，mPer1是果蝇周期基因（per）的序列同源物，在视交叉上核（SCN）中呈现出强劲的节律性表达。短时间暴露于足以重置生物钟的光照水平下，mPer1会迅速被诱导表达，剂量反应曲线显示，mPer1的诱导表达既呈现出互逆性，又与明显节律的相位移动高度相关。因此，无论是在黑暗表达的相位调节还是对光照的反应方面，mPer1都与粗糙脉孢菌生物钟基因frq最为相似。在视交叉上核内，诱导现象似乎存在定位，这与该昼夜节律中心中光敏感和光不敏感振荡器的定位一致。
