THE AMPLITUDE OF CIRCADIAN OSCILLATIONS - TEMPERATURE-DEPENDENCE, LATITUDINAL CLINES, AND THE PHOTOPERIODIC TIME MEASUREMENT
THE AMPLITUDE OF CIRCADIAN OSCILLATIONS - TEMPERATURE-DEPENDENCE, LATITUDINAL CLINES, AND THE PHOTOPERIODIC TIME MEASUREMENT
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DOI：
10.1177/074873049100600402
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发表时间：
1991-12-01
影响因子：
3.5
通讯作者：
TAKAMURA, T
中科院分区：
文献类型：
--
作者：
PITTENDRIGH, CS;KYNER, WT;TAKAMURA, T
本文提出了果蝇昼夜节律起搏器振幅不稳定性的几个命题。第一，起搏器运动的幅度与其周期不同，它明显依赖于温度。第二个是，起搏器振幅的纬度变化（北部较高）是负责两个非常不同的观察果蝇昼夜节律系统在连续较高的纬度。其中之一是D.极光对光线的相移反应，在一系列更北的应变中稳步减弱。另一个是关于D. littoralis在非常遥远的北方，是一个渐变的羽化活动的速度成为mammic（昼夜节律衰减）在恒定的黑暗中，衰减是在north.The第三个命题是关于一个合理的选择压力的渐变的起搏器幅度，我们提出的基础上直接观察到的两个渐变。强调两点：（1）起搏器的日振荡幅度随着夹带光脉冲（光周期）持续时间的增加而下降;（2）在整个繁殖季节，随着向两极移动，日光周期的持续时间稳步增加。保护起搏器振幅的选择（在繁殖季节）将产生我们提出的纬度渐变。第四，也是最后一个命题是，由于起搏器的日常运动的振幅系统地响应光周期的变化，振幅显然是一种方式和温度依赖的方式，昆虫的昼夜节律系统可能会感觉到季节性changes.These有关的温度和纬度依赖的起搏器振幅的命题可能是相关的比果蝇更广泛的昼夜节律起搏器。
This paper develops several propositions concerning die lability of die amplitude of Drosophila circadian pacemakers. The first is that the amplitude of the pacemaker's motion, unlike its period, is markedly temperature-dependent. The second is that latitudinal variation in pacemaker amplitude (higher in the north) is responsible for two very different sets of observations on Drosophila circadian systems at successively higher latitudes. One of these is a cline in D. auraria's phase-shifting response to light, which steadily weakens in a succession of more northerly strains. The other, concerning D. littoralis in the very far north, is a cline in the rate at which eclosion activity becomes arrhythmic (the circadian rhythm damps out) in constant darkness; damping is faster in the north.The third proposition concerns a plausible selection pressure for the cline in pacemaker amplitude that we propose underlies the two directly observed clines. Two points are emphasized: (1) The amplitude of the pacemaker's daily oscillation declines as the duration of the entraining light pulse (photoperiod) is increased; and (2) the duration of the daily photoperiods throughout the breeding season is steadily increased as one moves toward the poles. Selection for conservation of pacemaker amplitude (during the breeding season) would produce the latitudinal cline we propose. The fourth, and final proposition is that since the amplitude of the pacemaker's daily motion responds systematically to change in photoperiod, amplitude is clearly one way-and a temperature-dependent way-in which insect circadian systems may sense seasonal change.These propositions concerning the temperature and latitude dependence of pacemaker amplitude may be relevant to a wider array of circadian pacemakers than Drosophila.