Abstract
It is an established fact that circadian rhythmicity is often somehow involved in the physiology of photoperiodic induction. It is shown, however, that there are three possible ways in which such rhythmicity could be involved. For the most part available data are inadequate to discriminate among these three roles, only one of which is covered by “Bünning's Hypothesis.” Emphasis is given to a previously ignored possibility in which circadian organization is involved in photoperiodism“ut not as the clock responsible for the time-measurement. The meaning of circadian surfaces and their bearing on the interpretation of a widely used experimental protocol is developed.
Keywords: theoretical, biological clock, oscillator, resonance effects
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- Aschoff J. Desynchronization and resynchronization of human circadian rhythms. Aerosp Med. 1969 Aug;40(8):844–849. [PubMed] [Google Scholar]
- Pittendrigh C. S. Circadian rhythms, space research and manned space flight. Life Sci Space Res. 1967;5:122–134. [PubMed] [Google Scholar]
- Pittendrigh C. S., Eichhorn J. H., Minis D. H., Bruce V. G. Circadian systems, VI. Photoperiodic time measurement in Pectinophora gossypiella. Proc Natl Acad Sci U S A. 1970 Jul;66(3):758–764. doi: 10.1073/pnas.66.3.758. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pittendrigh C. S., Minis D. H. Circadian systems: longevity as a function of circadian resonance in Drosophila melanogaster. Proc Natl Acad Sci U S A. 1972 Jun;69(6):1537–1539. doi: 10.1073/pnas.69.6.1537. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Takimoto A., Hamner K. C. Effect of Temperature and Preconditioning on Photoperiodic Response of Pharbitis nil. Plant Physiol. 1964 Nov;39(6):1024–1030. doi: 10.1104/pp.39.6.1024. [DOI] [PMC free article] [PubMed] [Google Scholar]