spacer gif spacer gif spacer gif spacer gif Online submission spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

First published online November 1, 2006
Journal of Experimental Biology 209, 4414-4419 (2006)
Published by The Company of Biologists 2006
doi: 10.1242/jeb.02540
This Article
Right arrow Figures Only
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 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 Google Scholar
Google Scholar
Right arrow Articles by Bertrand, S.
Right arrow Articles by Sorci, G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Bertrand, S.
Right arrow Articles by Sorci, G.

Do carotenoid-based sexual traits signal the availability of non-pigmentary antioxidants?

Sophie Bertrand1,*, Bruno Faivre2 and Gabriele Sorci1,{dagger}

1 Laboratoire de Parasitologie Evolutive, Université Pierre et Marie Curie, CNRS UMR 7103, quai St Bernard, 75252 Paris cedex 05, France
2 Université de Bourgogne, UMR CNRS 5561 BioGéoSciences, Equipe Ecologie Evolutive, 6 Blvd Gabriel, 21000 Dijon, France

* Author for correspondence (e-mail: sbertran{at}snv.jussieu.fr)

Accepted 12 September 2006

Carotenoid-based signals are thought to be indicators of male quality because they must be obtained from the diet and might thus indicate the ability of individuals to gather high-quality food. However, carotenoids are also known to have important physiological functions as immunoenhancers and antioxidants, and, as such, carotenoid-based sexual traits have also been suggested to reflect the health and antioxidant status of their bearers. This last idea is based on the hypothesis that carotenoids that are allocated to sexual signals are no longer available for the detoxification system. Recently, this hypothesis has been challenged on the grounds that the antioxidant activity is not the main biological role of carotenoids. Instead, carotenoid-based sexual traits might signal the availability of other non-pigmentary antioxidant molecules that might protect carotenoids from free radical attacks and make them available for sexual advertisements. We tested this hypothesis in the zebra finch, a passerine species with a carotenoid-based signal: the colour of the bill. We simultaneously manipulated the availability of carotenoids and of a non-pigmentary antioxidant (melatonin) in the drinking water. If the antioxidant properties of melatonin protect carotenoids from oxidation, we predict that birds supplemented with melatonin should have redder bills than birds not supplemented with melatonin, and that birds supplemented with carotenoids and melatonin should have redder bills than birds supplemented with carotenoids alone. Our findings are in agreement with these predictions since carotenoid and melatonin supplementation had an additive effect on bill colour. To our knowledge this is the first experimental evidence that a non-pigmentary antioxidant enhances the expression of a carotenoid-based sexual trait.

Key words: carotenoids, free radicals, melatonin, oxidation, sexual advertisement, zebra finch




This article has been cited by other articles:


Home page
 J. Exp. Biol.Home page
C. Eraud, G. Devevey, M. Gaillard, J. Prost, G. Sorci, and B. Faivre
Environmental stress affects the expression of a carotenoid-based sexual trait in male zebra finches
J. Exp. Biol., October 15, 2007; 210(20): 3571 - 3578.
[Abstract] [Full Text] [PDF]


© The Company of Biologists Ltd 2006