Plant Physiol. Tips for Better Browsing
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
QUICK SEARCH:   [advanced]


     

Plant Physiology Preview
Published on November 20, 2003; 10.1104/pp.103.034223

This Article
Right arrow Full Text (Plant Physiology Preview (PDF))
Right arrow All Versions of this Article:
133/4/1517    most recent
pp.103.034223v1
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 Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Web of Science (28)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Ntefidou, M.
Right arrow Articles by Häder, D.-P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Ntefidou, M.
Right arrow Articles by Häder, D.-P.
Agricola
Right arrow Articles by Ntefidou, M.
Right arrow Articles by Häder, D.-P.

Received October 2, 2003
Returned for revision October 7, 2003
Accepted October 9, 2003

Photoactivated Adenylyl Cyclase Controls Phototaxis in the Flagellate Euglena gracilis

Maria Ntefidou , Mineo Iseki , Masakatsu Watanabe , Michael Lebert , and Donat-Peter Häder *

Department of Plant Ecophysiology, Friedrich-Alexander University, Staudtstrasse 5, 91058 Erlangen, Germany (M.N., M.L., D.-P.H.); National Institute for Basic Biology, Okazaki, Aichi, 444-8585 Japan (M.I., M.W.); Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency, Kawaguchi Saitama, 332-0012 Japan (M.I.); and Department of Photoscience, School of Advanced Sciences, Graduate University for Advanced Studies, Shonan Village, Hayama, Kanagawa,240-0193 Japan (M.W.)

* Corresponding author; email: dphaeder{at}biologie.uni-erlangen.de.

Euglena gracilis, a unicellular freshwater protist exhibits different photomovement responses, such as phototaxis (oriented movement toward or away from the light source) and photophobic (abrupt turn in response to a rapid increase [step-up] or decrease [step-down] in the light fluence rate) responses. Photoactivated adenylyl cyclase (PAC) has been isolated from whole-cell preparations and identified by RNA interference (RNAi) to be the photoreceptor for step-up photophobic responses but not for step-down photophobic responses (M. Iseki, S. Matsunaga, A. Murakami, K. Ohno, K. Shiga, C. Yoshida, M. Sugai, T. Takahashi, T. Hori, M. Watanabe [2002] Nature 415: 1047-1051). The present study shows that knockdown of PAC by RNAi also effectively suppresses both positive and negative phototaxis, indicating for the first time that PAC or a PAC homolog is also the photoreceptor for photoorientation of wild-type E. gracilis. Recovery from RNAi occurred earlier for step-up photophobic responses than for positive and negative phototaxis. In addition, we investigated several phototaxis mutant strains of E. gracilis with different cytological features regarding the stigma and paraxonemal body (PAB; believed to be the location for the phototaxis photoreceptor) as well as Astasia longa, a close relative of E. gracilis. All of the E. gracilis mutant strains had PAC mRNAs, whereas in A. longa, a different but similar mRNA was found and designated AlPAC. Consistently, all of these strains showed no phototaxis but performed step-up photophobic responses, which were suppressed by RNAi of the PAC mRNA. The fact that some of these strains possess a cytologically altered or no PAB demonstrates that at least in these strains, the PAC photoreceptor responsible for the step-up photophobic responses is not located in the PAB.




This article has been cited by other articles:


Home page
 Phil Trans R Soc BHome page
G. Jekely
Evolution of phototaxis
Phil Trans R Soc B, October 12, 2009; 364(1531): 2795 - 2808.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
V. Gradinaru, K. R. Thompson, F. Zhang, M. Mogri, K. Kay, M. B. Schneider, and K. Deisseroth
Targeting and Readout Strategies for Fast Optical Neural Control In Vitro and In Vivo
J. Neurosci., December 26, 2007; 27(52): 14231 - 14238.
[Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
ASPB Publications PLANT PHYSIOLOGY® THE PLANT CELL
Copyright © 2003 by the American Society of Plant Biologists