Circadian entrainment to red light in Drosophila requirement of Rhodopsin 1and Rhodopsin 6

Like most other insects, Drosophilavisual system is sensitive to the spectrum of light from ultraviolet to green but is insensitive to red light. The circadian rhythms of Drosophila, however, can be entrained by red light through unknown mechanisms. Here, we discovered the corresponding organ and photopigments responsible for the circadian entrainment of Drosophilato red light from light emitting diode. The entrainment was eliminated by the loss of photic input from compound eyes using eya2or norpAP24. We also found that the double Rhodopsin 1(ninaE) and Rhodopsinmutant was not entrained to red light. These results indicate that Drosophilacan entrain the circadian rhythm to red light through Rhodopsin 1and Rhodopsin 6in compound eyes.