[Advances in study on molecular mechanism of circadian clock in pineal gland].
The pineal gland functions as a central circadian oscillator in a variety of nonmammalian vertebrates. More recently, clock genes such as Per, Cry, Clock, and Bmal have been found in a variety of vertebrate clock structures including the avian pineal gland. The profiles of the temporal change of the clock gene expression in the avian pineal gland are more similar to those in the mammalian suprachiasmatic nucleus (SCN) of the hypothalamus. Avian pineal gland and mammalian SCN seem to share a fundamental molecular framework of the clock oscillator composed of a transcription/translation-based autoregulatory feedback loop. Some products of the clock genes serve as positive or negative regulators influencing the clock oscillation. The circadian time-keeping mechanism is also involved in several post-translational events. The above-mentioned processes play a quite important role in the stability of the oscillator and/or the photic-input pathway for entrainment of the clock.
Wang
Guo-Qing
GQ
Department of Physiology, Medical School, Soochow University, Suzhou 215007.
Tong
Jian
J
D000818:Animals; D001683:Biological Clocks / Q000235:genetics*; D002940:Circadian Rhythm / Q000235:genetics*; D005246:Feedback; D005786:Gene Expression Regulation; D006801:Humans; D010870:Pineal Gland / Q000502:physiology*; D013493:Suprachiasmatic Nucleus / Q000502:physiology