PDF neuron firing phase-shifts key circadian activity neurons in Drosophila
- Howard Hughes Medical Institute, National Center for Behavioral Genomics, Brandeis University, United States
- Penn Medicine (University of Pennsylvania Health System), United States
Abstract
Our experiments address two long-standing models for the function of the Drosophila brain circadian network: a dual oscillator model, which emphasizes the primacy of PDF-containing neurons, and a cell-autonomous model for circadian phase adjustment. We identify 5 different circadian (E) neurons that are a major source of rhythmicity and locomotor activity. Brief firing of PDF cells at different times of day generates a phase response curve (PRC), which mimics a light-mediated PRC and requires PDF receptor expression in the 5 E neurons. Firing also resembles light by causing TIM degradation in downstream neurons. Unlike light however, firing-mediated phase-shifting is CRY-independent and exploits the E3 ligase component CUL-3 in the early night to degrade TIM. Our results suggest that PDF neurons integrate light information and then modulate the phase of E cell oscillations and behavioral rhythms. The results also explain how fly brain rhythms persist in constant darkness and without CRY.
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Ethics
Animal experimentation: The research performed in this study on the fruit fly, Drosophila melanogaster, did not require approval by an ethics committee.
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© 2014, Guo et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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PDF neuron firing phase-shifts key circadian activity neurons in Drosophila
eLife 3:e02780.
https://doi.org/10.7554/eLife.02780
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