Journal
Abstract
Cryptochrome proteins are critical for circadian rhythms, but their function(s) is uncertain. Here we show that a mutation in a cryptochrome (dCRY) from the fruitfly Drosophila blocks an essential photoresponse of circadian rhythms, namely arrhythmicity under constant light conditions. We conclude that dCRY acts as a key photoreceptor for circadian rhythms and that there is probably no other comparable photoreceptor in this species.