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Updated: May 23, 2026
07:12
Circadian Entrainment of Drosophila Melanogaster
Published on: June 3, 2020
Phase-shifting the fruit fly clock without cryptochrome.
Christa Kistenpfennig1, Jay Hirsh, Taishi Yoshii
1Institute of Zoology, University of Regensburg, Regensburg, Germany.
Journal of Biological Rhythms
|April 6, 2012
Summary
Fruit flies lacking cryptochrome (CRY) can still adjust their internal clocks to light, showing that eyes play a role in circadian rhythm entrainment, even without CRY.
Area of Science:
- Chronobiology
- Insect Physiology
- Molecular Biology
Background:
- Cryptochrome (CRY) is the primary blue light photoreceptor for circadian entrainment in Drosophila melanogaster.
- Circadian entrainment to light-dark cycles can occur even in the absence of functional CRY.
Purpose of the Study:
- To investigate the role of CRY in light-mediated circadian entrainment in Drosophila.
- To characterize the phase response curves of CRY-deficient flies to light pulses of varying durations.
Main Methods:
- Monitoring phase response curves of cry(01) mutants and wild-type flies.
- Exposing flies to 1-hour, 3-hour, and 6-hour light pulses (1000 lux).
- Analyzing phase shifts in activity rhythms at different circadian times.
Main Results:
- CRY-less flies exhibit phase shifts in response to 1-hour light pulses, albeit with reduced magnitude.
- The eyes contribute to light sensitivity around dawn and dusk in CRY-deficient flies.
- CRY-less flies show impaired integration of light pulse duration compared to wild-type flies, with specific responses at circadian times 15 and 21.
Conclusions:
- Drosophila eyes possess CRY-independent light sensitivity crucial for circadian entrainment.
- CRY-less flies demonstrate altered responses to light pulse duration, indicating a complex role for CRY in circadian clock regulation.
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