Genetic Regulation of Circadian Rhythms in Drosophila

Studies in Drosophila have established many of the operating principles and molecular components that comprise circadian clocks, including those in humans. The discovery of the clock gene, period, has led to the idea that clocks consist of transcriptional feedback loops. In these loops, the activators, Clock and cycle, induce their own repressors, period and timeless. Phosphorylation modifies these components to control period length. Light synchronizes the clock to the environment through multiple photoreceptors, most notably the blue light photoreceptor, cryptochrome. These molecular clocks are distributed within a defined pacemaker neural network that sustains molecular and behavioral rhythmicity.