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Phase‐shifting of the circadian rhythm of eclosion in Drosophila pseudoobscura with temperature‐pulses∗∗

1973; Taylor & Francis; Volume: 4; Issue: 2 Linguagem: Inglês

10.1080/09291017309359375

0022-1945

Rudolf Maier,

Circadian rhythm and melatonin

Abstract A method for monitoring eclosion‐activity employing a photoelectric switch and an event‐recorder is described. Temperature‐pulses of 40 C and 4 min duration, interrupting the constant temperature of 20°C and offered during physiological darkness (red safe‐light), effectively and instantaneously shift the phase of the circadian rhythm of eclosion in Drosophila pseudoobscura. A weak type response‐curve showing varying delay‐shifts and no advance‐shift at all was obtained. In phaseshifting temperature‐pulses act instantaneously. The conclusion is based on data from two types of experiments. (a) Experiments employing phase‐response studies and (b) Experiments inducing arrythmicity with "singularity‐point"; treatment. Some consequences of direct temperature‐effects, such as age dependence in survival rate, are commented.