TEMPERATURE EFFECTS ON THE RESETTING OF THE PHASE OF THE NEUROSPORA CIRCADIAN-RHYTHM

Various temperatures relative to a 25 degrees C control have been appl ied as phase-resetting agents in release-assay experiments using the c onidiation rhythm of the mold Neurospora crassa. The larger the differ ence in temperature from the 25 degrees C control, the stronger the ph ase-resetting effects. Phase-resetting curves of the weak type (type 1 ) are observed for temperatures up to 28 degrees C and down to 22 degr ees C, whereas temperatures above 28 degrees C and less than 22 degree s C generally cause phase-resetting curves of the strong type (type 0) . Singularity behavior occurs at approximately 22 degrees C and 28 deg rees C when 25 degrees C is used as the control temperature. When a di fferent control of 29.5 degrees C is used in a release-assay experimen t and the resetting temperature is 25 degrees C, near-singularity beha vior is observed.