Holland, Eva M. and Harz, Hartmann and Uhl, Rainer and Hegemann, Peter (1997) Control of phobic behavioral responses by rhodopsin-induced photocurrents in Chlamydomonas. BIOPHYSICAL JOURNAL, 73 (3). pp. 1395-1401. ISSN 0006-3495, 1542-0086
Full text not available from this repository.Abstract
Both phototactic and photophobic responses of Chlamydomonas are mediated by a visual system comprising a rhodopsin photoreceptor. Suction pipette recordings have revealed that flash stimulation causes calcium currents into the eyespot and the flagella. These photocurrents have been suggested to be the trigger for all behavioral light responses of the cell. But this has never been shown experimentally. Here we describe a detection technique that combines electrical and optical measurements from individual algae held in a suction pipette. Thus it is possible to record photocurrents and flagellar beating simultaneously and establish a direct link between the two. We demonstrate that in Chlamydomonas only the photoreceptor current in conjuction with a fast flagellar current constitutes the trigger for photophobic responses. Within the time of the action-potential-like flagellar current, the flagella switch from forward to backward swimming, which constitutes the beginning of the photoshock reaction. The switch is accompanied by a complex frequency change and beating pattern modulation. The results are interpreted in terms of a general model for phototransduction in green algae (Chlorophyceae).
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | FLAGELLAR PHOTORESPONSES; CELLS HELD; CALCIUM CONTROL; REINHARDTII; MICROPIPETTES; WAVEFORM; REVERSAL |
| Subjects: | 500 Science > 540 Chemistry & allied sciences 500 Science > 570 Life sciences |
| Divisions: | Biology, Preclinical Medicine > Institut für Biochemie, Genetik und Mikrobiologie > Lehrstuhl für Biochemie I |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 30 Mar 2023 05:09 |
| Last Modified: | 30 Mar 2023 05:09 |
| URI: | https://pred.uni-regensburg.de/id/eprint/50584 |
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