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ID: 319759.0, MPI für Evolutionsbiologie / Evolutionary ecology
An experimental test of the immunocompetence handicap hypothesis in a teleost Fish: 11-ketotestosterone suppresses innate immunity in three-spined sticklebacks
Authors:Kurtz, Joachim; Kalbe, Martin; Langefors, Åsa; Mayer, Ian; Milinski, Manfred; Hasselquist, Dennis
Date of Publication (YYYY-MM-DD):2007-10
Title of Journal:The American Naturalist
Issue / Number:4
Start Page:509
End Page:519
Review Status:not specified
Audience:Not Specified
Abstract / Description:The immunocompetence handicap hypothesis (ICHH) provides a functional explanation for how sexual ornaments can provide honest signals of male quality. A key aspect of this hypothesis is that testosterone (T) has a bimodal effect: a higher T level enhances the expression of ornaments (increasing mating success and, ultimately, fitness); however, at the same time, it suppresses immune function. Tests of the latter assumption, which have focused mainly on aspects of adaptive immunity in birds, led to equivocal results. We performed a hormone-implant experiment in male three-spined sticklebacks (Gasterosteus aculeatus) to test the key assumptions of the ICHH in a fish, where the dominant circulating androgen is 11-ketotestosterone (11kT) rather than T. Males were implanted with 11-ketoandrostenedione, which is a natural precursor of 11kT. Each individual's circulating 11kT level, ornamentation, and immunocompetence were measured 2 weeks later. In addition, we quantified oxidative tissue damage because the ICHH has been hypothesized to work via oxidative stress. We found that the males' 11kT levels correlated positively with ornamentation but negatively with immunocompetence, in particular, measures of innate immunity. Moreover, there was a trend for fish with high 11kT levels to suffer more from oxidative stress. Thus, our data provide support for the ICHH.
Free Keywords:immunocompetence handicap; 11-ketotestosterone; innate immunity; oxidative stress; sexual selection; teleost fish
External Publication Status:published
Document Type:Article
Affiliations:MPI für Limnologie/Abt. Evolutionsökologie
External Affiliations:Institute for Evolution and Biodiversity, University of Münster, Hüfferstrasse 1, D-48149 Münster, Germany; Department of Biology, University of Bergen, Bergen N-5020, Norway; Department of Animal Ecology, Lund University, Ecology Building, 22362 Lund, Sweden;
Identifiers:ISSN:0003-0147 [ID-No:1]
DOI:10.1086/521316 [ID-No:2]
LOCALID:2563/S 38713 [Listen-Nummer/S-Nummer]
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