Effects of Temperature Perturbations on Circadian Conidiation in Neurospora

Abstract

Studies on the circadian rhythm of conidiation in the bd strain of Neurospora crassa Shear and Dodge have shown that temperature step-up and step-down perturbations produce phase advances and delays, respectively. Pulse-up and pulse-down treatments lead to both phase advances and delays. The resulting phase shifts can be very large, and few to no transients are observed.Small amplitude temperature cycles are capable of entraining the circadian rhythm, and holding bd at low temperatures appears to stop the circadian oscillator late in the subjective night (circadian time 2200). Aspects of the temperature responses that are somewhat unusual include the high sensivity, the lack of transients, and the phase at which the oscillator stops under low temperatures.