QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online June 29, 2006
Journal of Experimental Biology 209, 2739-2748 (2006)
Published by The Company of Biologists 2006
doi: 10.1242/jeb.02297

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Faucher, C. Articles by de Bruyne, M. Search for Related Content PubMed PubMed Citation Articles by Faucher, C. Articles by de Bruyne, M.

Behavioral responses of Drosophila to biogenic levels of carbon dioxide depend on life-stage, sex and olfactory context

Cécile Faucher^1,2, Manfred Forstreuter³, Monika Hilker² and Marien de Bruyne^1,*

¹ Freie Universität Berlin, Neurobiologie, Königin-Luise-Strasse 28-30, D-14195 Berlin, Germany
² Freie Universität Berlin, Angewandte Zoologie, Haderslebener Strasse 9, D-12163 Berlin, Germany
³ Technische Universität Berlin, Ökologie, Königin-Luise-Strasse 22, D-14195 Berlin, Germany

^* Author for correspondence at address 1 (e-mail: mdebruyn{at}zedat.fu-berlin.de); present address: Monash University, Biological Sciences, Wellington Road, Clayton VIC 3800, Australia

Accepted 25 April 2006

Drosophila melanogaster (Meigen) detects and uses many volatiles for its survival. Carbon dioxide (CO₂) is detected in adults by a special class of olfactory receptor neurons, expressing the gustatory receptor Gr21a. The behavioral responses to CO₂ were investigated in a four-field olfactometer bioassay that is new for Drosophila. We determined (1) whether the sensitivity of this response changes with odor context, and (2) if it depends on sex and life stage. When CO₂ was added to ambient air in one field and tested against ambient air in the three other fields, individually observed adults avoided CO₂ (0.1-1% above ambient), but did not respond to a low rise of 0.02%. We relate this behavior to measurements of CO₂ production in bananas and flies. When 0.02% CO₂ was combined with the odor of apple cider vinegar in one field of the olfactometer and tested against ambient air in the three other fields, the addition of CO₂ did not affect the attractiveness of apple cider vinegar alone. However, this combination of CO₂ and vinegar became repellent when it was tested against vinegar at ambient CO₂ concentrations in the three other fields. This `odor background effect' was female-specific, revealing a sexually dimorphic behavior. The new assay allowed us to test larvae under similar conditions and compare their behavior to that of adults. Like adults, they avoided CO₂, but with lower sensitivity. Larvae lacking neurons expressing Gr21a lost their avoidance behavior to CO₂, but kept their positive response to vinegar odor. Hence, Gr21a-expressing neurons mediate similar behaviors in larvae and adults.

Key words: olfaction, behavior, fruit, carbon dioxide, Drosophila melanogaster, larvae, receptor, odor context

This article has been cited by other articles:

				J. Y. Kwon, A. Dahanukar, L. A. Weiss, and J. R. Carlson The molecular basis of CO2 reception in Drosophila PNAS, February 27, 2007; 104(9): 3574 - 3578. [Abstract] [Full Text] [PDF]

				B. Gerber and R. F. Stocker The Drosophila Larva as a Model for Studying Chemosensation and Chemosensory Learning: A Review Chem Senses, January 1, 2007; 32(1): 65 - 89. [Abstract] [Full Text] [PDF]