Zeng H, Hardin P E, Rosbash M
Howard Hughes Medical Institute, Department of Biology, Brandeis University, Waltham, MA 02254.
EMBO J. 1994 Aug 1;13(15):3590-8. doi: 10.1002/j.1460-2075.1994.tb06666.x.
The Drosophila period gene (per) is a likely component of a circadian pacemaker. per protein (PER) participates in the regulation of its own expression, at least in part at the transcriptional level. There is at present no direct evidence that the effect of PER on its own transcription is intracellular. Results presented in this paper show that (i) the circadian oscillations of both per mRNA and PER protein are quantitatively similar in eye photoreceptor cells and in brain; (ii) constitutive overexpression of PER only in photoreceptors R1-R6 represses endogenous per RNA cycling in these cells but not in other per-expressing cells; (iii) the overexpression construct has no effect on locomotor activity rhythms. These results indicate that the autoregulation of per expression is a direct, intracellular event and suggest that each per-expressing cell contains an autonomous oscillator of which the per feedback loop is a component.
果蝇周期基因（per）可能是昼夜节律起搏器的一个组成部分。周期蛋白（PER）参与自身表达的调控，至少部分是在转录水平。目前尚无直接证据表明PER对自身转录的影响是在细胞内发生的。本文给出的结果表明：（i）周期信使核糖核酸（mRNA）和周期蛋白（PER）的昼夜振荡在眼感光细胞和脑中在数量上相似；（ii）仅在感光细胞R1 - R6中组成型过表达PER会抑制这些细胞中内源性周期RNA的循环，但不会抑制其他表达周期基因的细胞中的循环；（iii）过表达构建体对运动活动节律没有影响。这些结果表明周期基因表达的自动调节是一个直接的细胞内事件，并表明每个表达周期基因的细胞都包含一个自主振荡器，而周期反馈环是其组成部分。
