Biomaterial Database

Cell cycle oscillators. Temperature compensation of the circadian rhythm of cell division in Euglena. 1985

R W Anderson, and D L Laval-Martin, and L N Edmunds

The effects of different constant temperatures ranging from 16 degrees to 32 degrees C on the free-running, circadian rhythm of cell division were examined in axenic, photoautotrophic batch cultures of the unicellular algal flagellate Euglena gracilis Klebs. A comparative study was undertaken on the wild-type (Z strain) and a diuron-(DCMU)-resistant (ZR) strain. Although the overall growth rate (g) of both strains was rather dependent on temperature, lengthening increasingly at temperatures both higher and lower than the optimum range (about 23 degrees-29 degrees C), the free-running period (tau) of the oscillator hypothesized to underlie the overt rhythmicity in the cell division cycle (CDC) was found to be temperature-compensated over at least a 10 degrees C range. The degree of temperature compensation was most striking in the Z strain (Q10 = 1.05) over the permissive temperature interval of 22 degrees-32 degrees C, where periodic growth could occur. This Z strain had a slightly faster growth rate and displayed a higher degree of synchrony than that observed in the ZR strain, whose circadian clock was not as well compensated (Q10 = 1.23) over the permissive temperature interval of 18 degrees-28 degrees C. These results imply that the CDC is regulated by a circadian oscillator sharing the same features as those generating the many other overt biochemical and physiological circadian periodicities that have been documented for Euglena.

UI	MeSH Term	Description	Entries
D008027	Light	That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.	Light, Visible,Photoradiation,Radiation, Visible,Visible Radiation,Photoradiations,Radiations, Visible,Visible Light,Visible Radiations
D002455	Cell Division	The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.	M Phase,Cell Division Phase,Cell Divisions,Division Phase, Cell,Division, Cell,Divisions, Cell,M Phases,Phase, Cell Division,Phase, M,Phases, M
D002940	Circadian Rhythm	The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs or environmental and physiological stimuli.	Diurnal Rhythm,Nyctohemeral Rhythm,Twenty-Four Hour Rhythm,Nycthemeral Rhythm,Circadian Rhythms,Diurnal Rhythms,Nycthemeral Rhythms,Nyctohemeral Rhythms,Rhythm, Circadian,Rhythm, Diurnal,Rhythm, Nycthemeral,Rhythm, Nyctohemeral,Rhythm, Twenty-Four Hour,Rhythms, Circadian,Rhythms, Diurnal,Rhythms, Nycthemeral,Rhythms, Nyctohemeral,Rhythms, Twenty-Four Hour,Twenty Four Hour Rhythm,Twenty-Four Hour Rhythms
D005056	Euglena gracilis	A species of fresh-water, flagellated EUKARYOTES in the phylum EUGLENIDA.	Euglena gracili,gracilis, Euglena
D013045	Species Specificity	The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.	Species Specificities,Specificities, Species,Specificity, Species
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures