Indications for acceleration-dependent changes of membrane potential in the flagellate Euglena gracilis
Richter P, Schuster M, Meyer I, Lebert M, Häder DP (2006)
Publication Status: Published
Publication Type: Journal article
Publication year: 2006
Journal
Publisher: Springer Verlag (Germany)
Book Volume: 229
Pages Range: 101-108
Journal Issue: 2-4
DOI: 10.1007/s00709-006-0209-8
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.
Authors with CRIS profile
Peter Richter
Lehrstuhl für Zellbiologie
Martin Schuster
Lehrstuhl für Zellbiologie
Michael Lebert
Lehrstuhl für Zellbiologie
Donat-Peter Häder
Naturwissenschaftliche Fakultät
Involved external institutions
Germany (DE)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://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.
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