Institute of Zoology, University of Regensburg, Regensburg, Germany.
J Biol Rhythms. 2012 Apr;27(2):117-25. doi: 10.1177/0748730411434390.
The blue light photopigment cryptochrome (CRY) is thought to be the main circadian photoreceptor of Drosophila melanogaster. Nevertheless, entrainment to light-dark cycles is possible without functional CRY. Here, we monitored phase response curves of cry(01) mutants and control flies to 1-hour 1000-lux light pulses. We found that cry(01) mutants phase-shift their activity rhythm in the subjective early morning and late evening, although with reduced magnitude. This phase-shifting capability is sufficient for the slowed entrainment of the mutants, indicating that the eyes contribute to the clock's light sensitivity around dawn and dusk. With longer light pulses (3 hours and 6 hours), wild-type flies show greatly enhanced magnitude of phase shift, but CRY-less flies seem impaired in the ability to integrate duration of the light pulse in a wild-type manner: Only 6-hour light pulses at circadian time 21 significantly increased the magnitude of phase advances in cry(01) mutants. At circadian time 15, the mutants exhibited phase advances instead of the expected delays. These complex results are discussed.
蓝色光光感受器隐花色素（CRY）被认为是黑腹果蝇的主要生物钟光感受器。然而，即使 CRY 功能缺失，生物钟仍能适应光-暗循环。在这里，我们监测了 cry(01) 突变体和对照果蝇对 1 小时 1000 勒克斯光脉冲的相位反应曲线。我们发现 cry(01) 突变体在主观的清晨和傍晚相位提前它们的活动节律，尽管幅度减小。这种相位移动能力足以使突变体的适应变慢，表明眼睛在黎明和黄昏周围对生物钟的光敏感性有贡献。对于更长的光脉冲（3 小时和 6 小时），野生型果蝇显示出相位移动幅度大大增强，但 CRY 缺失的果蝇似乎在以野生型方式整合光脉冲持续时间的能力上受损：只有在生物钟时间 21 时的 6 小时光脉冲才能显著增加 cry(01) 突变体的相位提前幅度。在生物钟时间 15 时，突变体表现出相位提前，而不是预期的延迟。这些复杂的结果将进行讨论。
