A coupled pacemaker-slave model for the insect photoperiodic clock: interpretation of ovarian diapause data inDrosophila melanogaster
✍ Scribed by S. W. Gillanders; D. S. Saunders
- Book ID
- 104660862
- Publisher
- Springer-Verlag
- Year
- 1992
- Tongue
- English
- Weight
- 834 KB
- Volume
- 67
- Category
- Article
- ISSN
- 0340-1200
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✦ Synopsis
A coupled circadian oscillator model for the insect photoperiodic clock is described which consists of a hierarchically arranged pacemaker and slave. The pacemaker is self-sustained, temperature compensated, and entrainable by the light cycle; the slave is a damping oscillation receiving entrainment from two sources, from the pacemaker via a coupling factor, and also directly from the light. The damping slave oscillation is seen as the "photoperiodic oscillator", equivalent to that proposed earlier by . The present simulations describe the effect of the strength of the coupling factor between hypothetical short-and long-period pacemaker oscillations (modelled on the "clock" mutants per s and per L2 in Drosophila melanogaster) and a slave oscillation with a period of about 24 hours. The output is presented in terms of photoperiodic response curves and Nanda-Hamner, or resonance, plots. With a high coupling strength, the pacemakers strongly entrain the slave, but with a low coupling strength the slave's properties are more evident. The model is presented as a possible explanation for recent ovarian diapause data in D. rnelanogaster "clock" mutants , but also as a more general model for the role of the insect circadian system in seasonal time measurement.