Sehgal A, Price J, Young M W
Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10021.
Proc Natl Acad Sci U S A. 1992 Feb 15;89(4):1423-7. doi: 10.1073/pnas.89.4.1423.
Drosophila melanogaster born and reared in constant darkness exhibit circadian locomotor activity rhythms as adults. However, the rhythms of the individual flies composing these populations are not synchronized with one another. This lack of synchrony is evident in populations of flies commencing development at the same time, indicating that a biological clock controlling circadian rhythmicity in Drosophila begins to function without a requirement for light and without a developmentally imparted phase. It is possible to synchronize the phases of rhythms produced by dark-reared flies with light treatments ending as early as the developmental transition from embryo to first-instar larva: Light treatments occurring at developmental times preceding hatching of the first-instar larva fail to synchronize adult locomotor activity rhythms, while treatments ending at completion of larval hatching entrain these rhythms. The synchronized rhythmic behavior of adult flies receiving such light treatments suggests that a clock controlling circadian rhythms may function continuously from the time of larval hatching to adulthood.
在持续黑暗环境中出生并饲养的黑腹果蝇成虫表现出昼夜节律性运动活动节律。然而，构成这些群体的个体果蝇的节律彼此并不同步。这种缺乏同步性在同时开始发育的果蝇群体中很明显，这表明控制果蝇昼夜节律性的生物钟在开始运作时不需要光照，也不需要发育赋予的相位。早在从胚胎发育到一龄幼虫的过渡阶段，通过光照处理就有可能使黑暗饲养的果蝇产生的节律相位同步：在一龄幼虫孵化前的发育阶段进行光照处理，无法使成虫的运动活动节律同步，而在幼虫孵化完成时结束的处理则能使这些节律同步。接受这种光照处理的成年果蝇的同步节律行为表明，控制昼夜节律的生物钟可能从幼虫孵化时起就持续运作直至成年。
