Skip Navigation

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (4)
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Yoshimura, K.
Right arrow Articles by Kamiya, R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Yoshimura, K.
Right arrow Articles by Kamiya, R.
Agricola
Right arrow Articles by Yoshimura, K.
Right arrow Articles by Kamiya, R.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Plant and Cell Physiology, 2001, Vol. 42, No. 6 665-672
© 2001 Oxford University Press

The Sensitivity of Chlamydomonas Photoreceptor is Optimized for the Frequency of Cell Body Rotation

Kenjiro Yoshimura1 and Ritsu Kamiya Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Tokyo, 113-0033 Japan

For phototactic migration, Chlamydomonas scans the surrounding light environment by rotating the cell body with an eyespot located on the equator. The intensity of the light signal received by the eyespot should therefore change cyclically at the frequency of the cell body rotation. In this study, the response of the photoreceptor to cyclically changing light stimuli was analyzed using immotile mutant cells. To simulate the light intensity change perceived by a rotating cell, light stimuli were applied that consisted of a light phase with the intensity changing similar to a half cycle of a sine wave and a dark phase of the same length. The fluence rate at the peak of the sine wave was of the order of 1019 photons m–2 s–1, i.e. high intensity at which phototaxis is saturated. A photoreceptor current (PRC) was produced at the onset of each light phase. Interestingly, its amplitude varied depending on the frequency and was largest at 1–5 Hz, a frequency range similar to the frequency of cell body rotation. Experiments on the kinetics of the PRC indicate that the response was small at low frequency because of the inactivation of the PRC before full activation. In contrast, at high frequency the PRC was suppressed by adaptation to the repetitive stimuli. These characteristic kinetics of the PRC should be important for Chlamydomonas cells to extract information from the signals generated by the cell body rotation.

1 Corresponding author: E-mail, kenjiro@biol.s.u-tokyo.ac.jp; Fax, +81-3-5802-2734.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Plant CellHome page
P. Berthold, S. P. Tsunoda, O. P. Ernst, W. Mages, D. Gradmann, and P. Hegemann
Channelrhodopsin-1 Initiates Phototaxis and Photophobic Responses in Chlamydomonas by Immediate Light-Induced Depolarization
PLANT CELL, June 1, 2008; 20(6): 1665 - 1677.
[Abstract] [Full Text] [PDF]

Home page
 Plant Cell PhysiolHome page
K. Yoshimura, Y. Matsuo, and R. Kamiya
Gravitaxis in Chlamydomonas reinhardtii Studied with Novel Mutants
Plant Cell Physiol., October 15, 2003; 44(10): 1112 - 1118.
[Abstract] [Full Text] [PDF]


Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.