Sensory transduction of gravitaxis in Euglena gracilis

Streb C, Richter P, Ntefidou M, Lebert M, Häder DP (2002)

Publication Status: Published

Publication Type: Journal article

Publication year: 2002


Publisher: Elsevier

Book Volume: 159

Pages Range: 855-862

Journal Issue: 8

DOI: 10.1078/0176-1617-00769


Euglena gracilis is a single-celled freshwater flagellate which shows, among other movement behaviors, a negative gravitaxis (cells swim upward in the water column) and a pronounced phototaxis. Gravitaxis is most likely an active physiological mechanism, and the influence of various inhibitors on the gravitaxis in Euglena gracilis was tested using the fully automatic image analysis system ECO-TOX to elucidate the possible cellular mechanism of gravity perception and signal transduction. Substances such as the phosphodiesterase inhibitors theophylline, IBM-X and forskolin, which increase the intracellular cAMP concentration, enhance the precision of graviorientation of the cells measured shortly after incubation. Indomethacin, which decreases the intracellular cAMP concentration by inhibition of the adenylate cyclase, inhibited graviorientation. All inhibitors of calmodulin metabolism tested reduced the precision of gravitaxis in Euglena gracilis. Heparin and LiCl, which inhibit the IP3-pathway (block IP3 channels or formation of IP3, respectively) had no effect. The potassium channel blockers BaCl2 and CsCl showed an effect on the orientation behavior, while tetraethylammonium (TEA) had no influence. The protein phosphatase inhibitor, ocadaic acid, inhibited graviorientation at low concentrations. The data are discussed with respect to the current working model for gravitaxis in Euglena gracilis.

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Streb, C., Richter, P., Ntefidou, M., Lebert, M., & Häder, D.-P. (2002). Sensory transduction of gravitaxis in Euglena gracilis. Journal of Plant Physiology, 159(8), 855-862.


Streb, Christine, et al. "Sensory transduction of gravitaxis in Euglena gracilis." Journal of Plant Physiology 159.8 (2002): 855-862.

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