Indications for acceleration-dependent changes of membrane potential in the flagellate Euglena gracilis

Journal article


Publication Details

Author(s): Richter P, Schuster M, Meyer I, Lebert M, Häder DP
Journal: Protoplasma
Publisher: Springer Verlag (Germany)
Publication year: 2006
Volume: 229
Journal issue: 2-4
Pages range: 101-108
ISSN: 0033-183X


Abstract


The effects of the calcium sequester EGTA on gravitactic orientation and membrane potential changes in the unicellular flagellate Euglena gracilis were investigated during a recent parabolic-flight experiment aboard of an Airbus A300. In the Course of a flight parabola, an acceleration profile is achieved which yields Subsequently about 20 s of hypergravity (1.8 g(n)), about 20 s of microgravity, and another 20 s of hypergravity phases. The movement behavior of the cells was investigated with real-time, computer-based image analysis. Membrane potential changes were detected with a newly developed photometer which measures absorption changes of the membrane potential-sensitive probe oxonol VI. To test whether the data obtained by the oxonol device were reliable, the signal of non-oxonol-labelled cells was recorded. In these samples, no absorption shift was detected. Changes of the oxonol VI signals indicate that the cells depolarize during acceleration (very obvious in the step from microgravity to hypergravity) and slightly hyperpolarize in microgravity. which can possibly be explained with the action of Ca-ATPases. These signals (mainly the depolarization) were significantly suppressed in the presence of EGTA (5 mM). Gravitaxis in parallel was also inhibited after addition of EGTA. Initially. negative gravitaxis was inverted into a positive one. Later, gravitaxis was almost undetectable.



FAU Authors / FAU Editors

Häder, Donat-Peter Prof. Dr.
Naturwissenschaftliche Fakultät
Lebert, Michael PD Dr.
Lehrstuhl für Zellbiologie
Richter, Peter Dr.
Lehrstuhl für Zellbiologie
Schuster, Martin
Lehrstuhl für Zellbiologie


How to cite

APA:
Richter, P., Schuster, M., Meyer, I., Lebert, M., & Häder, D.-P. (2006). Indications for acceleration-dependent changes of membrane potential in the flagellate Euglena gracilis. Protoplasma, 229(2-4), 101-108. https://dx.doi.org/10.1007/s00709-006-0209-8

MLA:
Richter, Peter, et al. "Indications for acceleration-dependent changes of membrane potential in the flagellate Euglena gracilis." Protoplasma 229.2-4 (2006): 101-108.

BibTeX: 

Last updated on 2018-19-04 at 03:38