English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
  The interplay between gonadal steroids and immune defence in affecting a carotenoid-dependent trait

Casagrande, S., & Groothuis, T. G. G. (2011). The interplay between gonadal steroids and immune defence in affecting a carotenoid-dependent trait. Behavioral Ecology and Sociobiology, 65(10), 2007-2019. doi:10.1007/s00265-011-1210-6.

Item is

Files

show Files

Locators

show

Creators

show
hide
 Creators:
Casagrande, Stefania1, Author              
Groothuis, Ton G. G., Author
Affiliations:
1University of Groningen, The Netherlands , ou_persistent22              

Content

show
hide
Free keywords: color dihydrotestosterone estradiol humoral immunity ichh ornament srbc testosterone
 Abstract: The hypothesis that sexual ornaments are honest signals of quality because their expression is dependent on hormones with immune-depressive effects has received ambiguous support. The hypothesis might be correct for those signals that are carotenoid-dependent because the required carotenoid deposition in the signal, stimulated by testosterone, might lower the carotenoid-dependent immune defence of the organism. Two pathways underlying this androgen-dependent honest signaling have been suggested. Firstly, androgens that are needed for ornament expression may suppress immune defence, a cost that only high-quality animals can afford. Alternatively, immune activation may downregulate the production of androgens in low-quality individuals. Which of these alternatives is correct, and to what extent these effects are mediated by the different metabolites of androgens, remain open questions. To provide answers to these questions, we manipulated the levels of testosterone (T), 5α-dihydrotestosterone (DHT), and 17-β-estradiol (E2) in diamond doves Geopelia cuneata, a species in which both sexes exhibit a carotenoid-dependent, androgen-regulated red-orange periorbital ring of bare skin. On the first day of the experiment (day0), we inserted steroid-releasing implants into groups of birds and on day14, we subjected half of the birds to an immunological challenge by immunizing them with sheep red blood cells (SRBC). In females, but not in males, androgen but not estradiol treatments reduced antibody production to SRBC. In addition, the immunological challenge reduced redness and size of the trait as well as androgens levels in both sexes and in all treatments. This indicates that an immunological challenge can lower circulating T at the cost of the trait expression. These findings are in accordance with both pathways postulated in the immunocompetence-handicap hypothesis, but do not entirely support the idea that the immunosuppressive effect of androgens yields honest signaling since both T and DHT were not immunosuppressive in males, for which sexual signaling is supposed to be especially important.

Details

show
hide
Language(s):
 Dates: 2011
 Publication Status: Published in print
 Pages: -
 Publishing info: -
 Table of Contents: -
 Rev. Type: -
 Identifiers: DOI: 10.1007/s00265-011-1210-6
ISSN: 0026501112
 Degree: -

Event

show

Legal Case

show

Project information

show

Source 1

show
hide
Title: Behavioral Ecology and Sociobiology
Source Genre: Journal
 Creator(s):
Affiliations:
Publ. Info: Heidelberg : Springer-Verlag
Pages: - Volume / Issue: 65 (10) Sequence Number: - Start / End Page: 2007 - 2019 Identifier: ISSN: 0340-5443
CoNE: https://pure.mpg.de/cone/journals/resource/954925518617