L N Edmunds, D E Tay, D L Laval-Martin
The cell division rhythm in Euglena gracilis Klebs (Z strain) freeruns with a circadian period (30.2 +/- 1.8 hours for 156 monitored oscillations) in aerated, magnetically stirred, 8-liter, axenic batch cultures grown photoautotrophically at 25 degrees C in LD: 3,3, (7,500 lux, cool-white fluorescent) 6-hour light cycles from the moment of inoculation. Cell number was measured at 2-hour intervals with an automatic fraction collector and Coulter Electronic Particle Counter. At different circadian times throughout the 30-hour division cycle, 3-hour light perturbations were imposed on free-running cell populations by giving light during one of the intervals when dark would have fallen in the LD: 3,3 regimen...
July 1982: Plant Physiology