Entrainment and phase shifting of the circadian rhythm of cell division by light in cultures of the achlorophyllous ZC mutant ofEuglena gracilis |
| |
Authors: | Dr. Isabelle A. Carré Ady S. Oster Danielle L. Laval-Martin Leland N. Edmunds Jr. |
| |
Affiliation: | (1) Department of Anatomical Sciences, State University of New York, Stony Brook, New York, USA;(2) Laboratory of Biological Membranes, University of Paris, Paris, France;(3) Division of Biological Sciences, State University of New York, Life Sciences Bldg., Room 370, 11794 Stony Brook, New York, USA |
| |
Abstract: | The photosynthesis-deficient ZC mutant ofEuglena gracilis Klebs (strain Z) was cultured at 16°C on an aerated, magnetically stirred, mineral medium containing 0.1% ethanol (pH 7.0). Cell division could be entrained by a 12: 12 light: dark cycle (LD: 12, 12) or even by a one-pulse skeleton photoperiod (LD: 1,23) The rhythm free-ran in DD for at least 8 days with a circadian period (=25.5 h) in populations that had been previously entrained by LD. The freerunning rhythm could be phase-shifted by a single 1-h light pulse (3000 lx). The strong (Type 0) phase-response curve derived from the resetting effects of such signals given at different circadian times was similar to that for the photosynthetic wild-type strain. These results demonstrate that the presence of a functional chloroplast compartment is not necessary for the circadian clock to function inEuglena and suggest that phase resetting of the circadian clock by light occurs via a similar pathway in both photosynthetic and non-photosynthetic cell types. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|