Phosphorylation of a receptor controls how messages from the neuropeptide PDF—which influence dawn and dusk activities in Drosophila—are curtailed on a daily basis to adapt the circadian clock to changing daylight.
Taghert Lab identifies off switch for a set of circadian clock–controlled behaviors in flies
![microscope image of the Drosophila brain, fixed and double-stained for PDF (red fluorescence) and PDF-R (green fluorescense)](https://neuroscience.wustl.edu/wp-content/uploads/2022/11/pdf-header-300x200.png)