BEHAVIOR IN LIGHT DARK CYCLES OF DROSOPHILA MUTANTS THAT ARE ARRHYTHMIC, BLIND, OR BOTH
BEHAVIOR IN LIGHT DARK CYCLES OF DROSOPHILA MUTANTS THAT ARE ARRHYTHMIC, BLIND, OR BOTH
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DOI：
10.1177/074873049300800106
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发表时间：
1993-03-01
影响因子：
3.5
通讯作者：
HALL, JC
中科院分区：
文献类型：
--
作者：
WHEELER, DA;HAMBLENCOYLE, MJ;HALL, JC
果蝇的某些节律突变会在恒定条件下导致心律失常的运动活动（和非周期性羽化）。然而，在光-暗（LD）循环中，此类突变体在开灯时的高活性水平和关灯时的低活性水平之间表现出明显的波动。与之前的一些结论相反，我们的数据强烈表明，在 LD 条件下，period0 (per0) 成年人只是“被迫”表现出周期性行为。这些实验涉及 8、12、16 和 24 小时 LD 循环的应用，其中心律失常突变体可能会受到任何这些周期性的影响，而野生型果蝇在循环条件下往往表现出约 24 小时的周期，其 T 值与 24 的差异 > 8 小时。在相移实验中，发现表达与节律性相关的基因型的果蝇比 24 小时提前了 5 小时。提前开灯后 2 天的时间；每 0 名成年人的运动峰值相位改变得更快。在无眼或失明的果蝇表现出正常夹带的事实背景下，假设如果后一种单突变类型中看到的强迫节律仅由通过外部光感受器输入的光介导，那么携带这种视觉突变和 per0 的双突变果蝇不应与 LD 周期同步。由于相当大比例的双突变体确实同步（LD 12:12），因此表明参与强制节律的视觉线索可以通过相同的眼外光感受器输入，这些感受器通常促进果蝇的节律系统。
Certain of the rhythm mutations in Drosophila melanogaster lead to arrhythmic locomotor activity (and aperiodic eclosion) in constant conditions. In light-dark (LD) cycles, however, such mutants exhibit clear fluctuations between high levels of activity when the lights are on and much lower ones when they are off. Our data, in contrast to some previous conclusions, strongly suggest that period0 (per0) adults are, in LD conditions, merely being ''forced'' into exhibiting periodic behavior. These experiments involved application of 8-, 12-, 16-, and 24-hr LD cycles, in which the arrhythmic mutant could have any of these periodicities imposed upon it, whereas wild-type flies tended to exhibit periods of about 24 hr in cycling conditions whose T values were >8 hr different from 24. In phase-shift experiments, it was found that Drosophila expressing genotypes associated with rhythmicity achieved a 5-hr advance over a 2-day period following an advanced lights-on; per0 adults altered the phase of their locomotor peaks more rapidly. Against a background of the fact that eyeless or blind flies exhibit normal entrainment, it was hypothesized that double-mutant flies- carrying such visual mutations and per0 as well-should not synchronize to LD cycles, if the forced rhythms seen in the latter single-mutant type are mediated solely by light input through the external photoreceptors. Since an appreciable proportion of the double mutants did synchronize (to LD 12:12), it is thus suggested that the visual cues involved in forcing rhythmicity could be input through the same extraocular photoreceptors that, in general, subserve the fly's rhythm system.