Abstract
The circadian rhythm is an adaptation system to a light-dark 24 hr cycle in nearly all organisms. Its center in mammals is located in the suprachismatic nucleus (SCN) of the hypothalamus, however, competitive studies for the last several years revealed that molecular clocks are located not only in SCN but also in various peripheral tissues, even in cultured cells. Moreover, molecular mechanism of circadian oscillation is based on transcriptional regulation composing of negative feedback loops of clock gene regulation. Our recent systematic analyses of canonical clock genes expression identified three clock elements (E-box, RORE, and DBPE). Using in vitro real-time oscillation monitoring system, we disclosed regulatory mechanisms of mammalian clock genes including Period, Bmal1. [Jpn J Physiol 55 Suppl:S53 (2005)]
