Temperature-compensated oscillations in respiration and cellular protein content in synchronous cultures of Acanthamoeba castellanii.

Publisher Website
Google Scholar
Abstract
Synchronous cultures of the soil amoeba A. castellanii, established by a selection procedure, show significant oscillations of respiration (O2 consumption) and total cell protein. There was little difference between the period of these oscillations, which averaged 76 min, although the 5 incubation temperatures used varied between 20-30.degree. C and the cell division time increased from 7.8-16 h. The phase of these oscillations also corresponded approximately at all incubation temperatures. Similar observations made over the whole division cycle at 3 temperatures indicated that similar oscillations occurred, with a constant period of 65 min, although these data were too variable to show this unequivocally. Control (asynchronous) cultures show that the oscillations are not a consequence of metabolic perturbation produced by the centrifugal selection procedure. These temperature-compensated epigenetic oscillations may serve a dual role in cell cycle and circadian timekeeping and the cell cycle time is quantized.