| | 1 | Author
| Margarete Hoffmans-Hohn, W. Olfgang, M. Artin, Klaus Brinkm | Requires cookie* | | | Title
| Multiple Periodicities in the Circadian System of Unicellular Algae  | | | | Abstract
| Three periodicities in the circadian range are observed when m easuring circadian parameters of unicellular organisms in long running experim ents (m ore than 15 days). This is dem onstrated for different organisms (Chlamydomonas, Euglena, C hlorella) and different parameters (auto kinesis, extracellular pH, C 0 2-and 0 2-partial pressure). H aving excluded analytical and experimental artefacts {i.e. filter leakage and subpopulation effects), the m ultiple periodicities have to be interpreted in a physiological m odel. The three p eriod icities always exhibit two common features: The locations o f the side peaks are sym m etrical to the m iddle peak and their energy contribution is always the same. W e therefore favour the m odel o f m ultiplicative coupling between the circadian oscillator and a low frequency oscillator m odulating the am plitude o f the circadian rhythm. Since the low frequency rhythm is not correlated to any exogenously running periodicity o f the experim ental surroundings, it is considered as generated by an endogenous oscillator. This shows the existence o f different biological long tim e oscillators in one single cell and contradicts the so-called m aster-clock hypothesis stating that one cell has only one clock related oscillator. | | | |
Reference
| Z. Naturforsch. 39c, 791—8 (1984); received D ecem ber 5 1983/M arch 17 1984 | | | |
Published
| 1984 | | | |
Keywords
| Circadian Rhythm, pH-Rhythm, Chlamydomonas, Euglena, Chlorella | | | |
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| default:Reihe_C/39/ZNC-1984-39c-0791.pdf | | | | Identifier
| ZNC-1984-39c-0791 | | | | Volume
| 39 | |
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