Identification and Characterization of The Photorecetor of Insect Circadian Clock

本文研究了果蝇（Drosophilamelanogaster）和突变果蝇（Drosophilamelanogaster）在不同光照条件下的运动活动。在昼夜运动活动降低到最低水平的主观夜间，给予正常果蝇不同强度的短闪光。强光刺激引起（1）光刺激期间运动活动增加和（2）光刺激期间的运动活动增加。（3）光刺激期间的运动活动增加和（4）光刺激期间的运动活动增加。（5）光刺激期间的运动活动增加和（6）光刺激期间的运动活动增加。（7）光刺激期间的运动活动增加和（7）光刺激期间的运动活动增加。（8）光刺激期间的运动活动增加和（7）光刺激期间的运动活动增加。（8）光刺激期间的运动活动增加和（7）光刺激期间的运动活动增加。（9）光刺激期间的运动活动增加和（7）光刺激期间的运动活动增加和（8）光刺激期间的运动活动增加。（10）光刺激期间的运动活动增加和（10）光刺激期间的运动活动增加由于闪光的夹带，昼夜运动活动的变化。然而，较低强度的闪光在刺激期间仅诱导运动活动的增加，而不会使昼夜活动发生相移。眼睛突变体，如sine oculis或眼睛缺失，其中总复眼的结构缺失，正常果蝇的运动活动不存在直接光反应，而无眼果蝇的昼夜节律活动几乎出现正常的相移，这表明：（1）昼夜节律钟的光感受器不是复眼;然而，运动活动的直接光反应是由复眼的输入控制的。这表明单眼不参与昼夜节律钟的光响应。由于昼夜节律钟的光感受器仍然不清楚，本研究揭示了视觉系统的输入影响运动活动而不重置活动的存在。

Locomotor activity of the adult normal and mutant fruit flies Drosophila melanogaster was investigated under various lighting conditions.Normal flies were given a short light flash of various intensities during the subjective night when the circadian locomotor activity decreases to the minimum level.An intense light induced both (1) an increase of locomotor activity during the light stimulation and (2) a phase-shift of the circadian locomotor activities as a result of the entrainment by the light flash.Flashes of lower intensity, however, induced only the increase of locomotor activity during the stimulation without phase-shifting the circadian activity.Eye mutants, like sine oculis or eye-missing where the structures of the total compound eyes are missing, did not show the direct light response to the flash while they showed almost normal phase-shift of the circadian activity.The dissociation of the locomotor activities in the normal flies and the absence of the direct light response in the eye-less mutants suggest (1) that the photoreceptor (s) of the circadian clock is not the compound eyes and (2) that the direct light response of the locomotor activity is nevertheless controlled by the input from the compound eyes.The ocelli-less mutants also showed a normal phase-shift in response to the light flash suggesting that the ocelli are not involved in the photoresponse of the circadian clock.While the nature of the photoreceptor of the circadian clock still remained unclear, this study has revealed the presence an input from the visual system affecting the locomotor activity without resetting the activity.