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Updated: Jul 18, 2026
Single-cell Resolution Fluorescence Live Imaging of Drosophila Circadian Clocks in Larval Brain Culture
Published on: January 19, 2018
Mechanisms of clock output in the Drosophila circadian pacemaker system
Paul H Taghert1, Orie T Shafer
1Department of Anatomy and Neurobiology, Washington University Medical School, Saint Louis, MO 63110, USA. taghertp@pcg.wustl.edu
Abstract:
Molecular oscillations that underlie the circadian clock are coupled to different output signals by which daily rhythms in downstream events are evoked and/or synchronized. Here the authors review the literature that describes circadian output mechanisms in Drosophila. They begin at the most proximal level, within oscillator cells themselves, by surveying studies of rhythmic gene expression within Drosophila heads. Next the authors describe the several neuron groups that compose the circadian pacemaker network underlying rhythmic locomotor activity, and they detail current models of how that network is organized and coordinated. The authors outline the body of evidence that describes a role for the neuropeptide pigment dispersing factor (PDF) as a circadian transmitter in the fly brain. Finally, in the context of PDF, they consider studies that address mechanisms of signaling from the circadian pacemaker network to downstream neurons and nonneuronal cells that directly control rhythmic outputs.
Insights
This review explores how molecular oscillations in Drosophila
Area of Science:
- Chronobiology
- Neuroscience
- Molecular Biology
Background:
- Circadian clocks regulate daily rhythms through molecular oscillations.
- Understanding circadian output mechanisms is crucial for deciphering biological timing.
- Drosophila serves as a model organism for studying circadian rhythms.
Purpose of the Study:
- To review the literature on circadian output mechanisms in Drosophila.
- To detail the organization and coordination of the circadian pacemaker network.
- To highlight the role of pigment-dispersing factor (PDF) in circadian signaling.
Main Methods:
- Survey of rhythmic gene expression studies in Drosophila heads.
- Description of neuron groups composing the circadian pacemaker network.
- Analysis of models for network organization and coordination.
- Review of evidence for pigment-dispersing factor (PDF) as a circadian transmitter.
- Examination of signaling mechanisms from pacemaker network to downstream targets.
Main Results:
- Rhythmic gene expression is observed within Drosophila oscillator cells.
- The circadian pacemaker network comprises several key neuron groups.
- Pigment-dispersing factor (PDF) is identified as a crucial circadian transmitter.
- Mechanisms of signaling from the pacemaker network to downstream cells are elucidated.
Conclusions:
- Circadian output in Drosophila involves complex molecular oscillations and neural networks.
- Pigment-dispersing factor (PDF) plays a central role in transmitting circadian information.
- Further research into signaling pathways will enhance understanding of daily rhythm regulation.
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