Hanai Shuji, Ishida Norio
Clock Cell Biology Research Group, National Institute of Advanced Industrial Science and Technology, Higashi, Japan.
Neuroreport. 2009 May 27;20(8):755-8. doi: 10.1097/WNR.0b013e32832a7c4e.
Light is one of the most important time cues for entrainment of the circadian clock. Drosophila circadian photoreception is mediated by cryptochrome in clock neurons and by rhodopsins in photic organs. We generated Rh5 mutants to elucidate circadian photoreception by rhodopsins. The Rh1, Rh5 and Rh6 mutants were combined with cry, and entrained to a 6-h delayed photoperiod. The cry, Rh1, Rh5 and Rh6 quadruple mutant became entrained by white light. In contrast, reentrainment to green and yellow light was abolished in the cry, Rh1, Rh5 and Rh6 quadruple mutant, and remarkably slowed in the cry, Rh1 and Rh6 triple mutant. These results suggest that cry, Rh1, Rh5 and Rh6 are essential for circadian photoentrainment to green and yellow light.
光是昼夜节律时钟同步最重要的时间线索之一。果蝇的昼夜节律光感受由时钟神经元中的隐花色素和感光器官中的视紫红质介导。我们生成了Rh5突变体以阐明视紫红质介导的昼夜节律光感受。将Rh1、Rh5和Rh6突变体与cry相结合，并使其适应延迟6小时的光周期。cry、Rh1、Rh5和Rh6四重突变体被白光同步。相比之下，cry、Rh1、Rh5和Rh6四重突变体对绿光和黄光的重新同步被消除，而在cry、Rh1和Rh6三重突变体中则显著减慢。这些结果表明，cry、Rh1、Rh5和Rh6对于昼夜节律对绿光和黄光的光同步至关重要。
