Circadian clocks during embryonic and fetal development.

摘要: Circadian rhythmicity is a fundamental characteristic of organisms, which helps ensure that vital functions occur in an appropriate and precise temporal sequence accordance with cyclic environmental changes. Living beings are endowed system biological clocks measure time on 24-hr basis, termed the circadian timing system. In mammals, organized as master clock located suprachiasmatic nucleus (SCN) hypothalamus, commanding peripheral almost every tissue body. At cell level, interlocking transcription/translation feedback loops genes Bmal-1, Clock, Per1-2, Cry1-2, named genes, their protein products results oscillation involved cellular function. During gestation, conceptus follows complex dynamic program by it simultaneously fit to develop live environment provided its mother prepare for very different will experience after birth. It has been known number years tells fetus day season year, uses this information set phase fetal neonatal rhythms. There evidence maternal rhythm melatonin one signals fetus. last few years, study development turned investigation oscillatory expression possible role development, answering questions organization Emerging shows expressed oocyte during early late embryo/fetal organs rat primate. The data available raise intriguing possibility SCN tissues may be commanded separate signals. rapid methodological conceptual advances chronobiology help unravel how developing embryo faces plastic period life.