A phase-dependent delay of the chick pineal rhythm in rate of thymidine incorporation by brief exposure to aphidicolin.
Cultured chick pineal glands show a persistent rhythm in the rate of cumulative incorporation of thymidine into DNA. In this study we have examined the effects of pulse-exposure to aphidicolin in the dark on the first day of culture on thymidine incorporation during the second and third days of culture in the dark with aphidicolin-free medium. The phase of the rhythm in the rate of thymidine incorporation was delayed in a concentration-dependent manner by a 4-hr exposure to aphidicolin, commencing in the final hour of the photoperiod. This effect was phase-dependent and not seen when exposure to aphidicolin began earlier in the photoperiod.
Wainwright
S D
SD
Biochemistry Department, Dalhousie University, Halifax, Nova Scotia, Canada.
Wainwright
L K
LK
D000818:Animals; D016590:Aphidicolin / Q000494:pharmacology*; D002645:Chickens; D002940:Circadian Rhythm / Q000187:drug effects*; D004261:DNA Replication / Q000502:physiology; D003624:Darkness; D009924:Organ Culture Techniques; D017440:Photoperiod; D010870:Pineal Gland / Q000187:drug effects* / Q000378:metabolism; D013936:Thymidine / Q000378:metabolism*
D016590:Aphidicolin; D013936:Thymidine