Document Type
Article
Publication Title
Journal of Experimental Biology
Publication Date
8-15-2011
Keywords
yolk testosterone, phytohaemagglutinin assay, bactericidal assay, PHA, trade-off, Troglodytes aedon
Abstract
Maternally derived testosterone in the eggs of birds may benefit nestlings by increasing various aspects of their growth, condition and behavioral development, but these benefits may come at a cost, including suppression of immune responsiveness. Experiments on a variety of species in which in ovo levels of testosterone have been experimentally increased have produced mixed results; some have found increased growth and suppressed immune function of nestlings whereas others have found the opposite. In an attempt to clarify the relationship between in ovo testosterone and nestling size, mass, health state and immune responsiveness, we experimentally increased levels of testosterone in the eggs of house wrens (Troglodytes aedon). We simultaneously determined the size, mass, hematocrit (a measure of health state), cutaneous immune response to phytohaemagglutinin and plasma bactericidal activity of nestlings near the time of fledging. We predicted that nestlings hatching from testosterone-injected eggs would exhibit lower immune responsiveness, but achieve greater mass, size and condition, than nestlings hatching from vehicle-injected control eggs. Instead, we found that nestlings hatching from testosterone-injected eggs had a weaker cutaneous immune response but greater bactericidal activity than those hatching from control eggs. They did not, however, differ significantly in mass, size or hematocrit from controls. These results suggest that experimentally increased in ovo testosterone induced a trade-off between bactericidal activity and the cutaneous immune response. The opposite responses by two different measures of immune function to experimentally increased in ovo testosterone underscore the importance of including multiple immune assays when investigating the potential for trade-offs with the immune system and other physiological functions.
Funding Source
This research was funded in part by a National Science Foundation (NSF) grant (IBN-0316580 to C.F.T., S.K.S. and L. A. Vogel). Support for S.G.C. throughout the summer came from an NSF REU Supplemental Award (IOS-0718140 to S.K.S. and C. G. Hamaker). C.A.B. was supported by a postdoctoral fellowship from the Program of Excellence in Neuroscience and Behavior, College of Arts and Sciences, Illinois State University.
Recommended Citation
Sandrine G. Clairardin, Craig A. Barnett, Scott K. Sakaluk, Charles F. Thompson; Experimentally increased in ovo testosterone leads to increased plasma bactericidal activity and decreased cutaneous immune response in nestling house wrens. J Exp Biol 15 August 2011; 214 (16): 2778–2782. doi: https://doi.org/10.1242/jeb.054833
DOI
10.1242/jeb.054833
Comments
First published in Journal of Experimental Biology (2011): https://doi.org/10.1242/jeb.054833
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