Immune activation affects chemical sexual ornaments of male Iberian wall lizards
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Many animals use chemical signals in sexual selection, but it is not clear how these sexual traits might have evolved to signal honestly male condition. It is possible that there is a trade-off between maintaining the immune system and the elaboration of ornaments. We experimentally challenged the immune system of male Iberian wall lizards, Podarcis hispanica, with a bacterial antigen (lipopolysaccharide), without pathogenic effects, to explore whether the immune activation affected chemical ornaments. Immune activation resulted in decreased proportions of a major chemical in femoral secretions (cholesta-5,7-dien-3-ol = provitamin D3) known to be selected in scent of males by females and which active form (vitamin D) has a variety of important effects on immune system function. This result suggests the existence of a potential trade-off between physiological regulation of the immune system and the allocation of essential nutrients (vitamins) to sexual chemical ornaments in male lizards.
KeywordsSexual signals Immune response Femoral glands Vitamin D Sexual selection
We thank three anonymous reviewers for helpful comments and “El Ventorrillo” MNCN Field Station for use of their facilities. Financial support was provided by the projects MEC-CGL2005-00391/BOS and MCI-CGL2008-02119/BOS and by an “El Ventorrillo” CSIC grant to MG. The experiments enforced all Spanish laws and were performed under license from the Environmental Organisms of Madrid Community.
- Aitchison J (1986) The statistical analysis of compositional data. Chapman and Hall, LondonGoogle Scholar
- Hill RW, Wyse GA, Anderson M (2008) Animal physiology,, 2nd edn. Sinauer Associates, Sunderland, MAGoogle Scholar
- Janeway CA, Travers P, Walport M, Shlomchik M (2001) Immunobiology. The immune system in health and disease, 5th edn. Garland Publishing, New YorkGoogle Scholar
- Mason RT (1992) Reptilian pheromones. In: Gans C, Crews D (eds) Biology of the Reptilia vol 18. University of Chicago Press, Chicago, pp 114–228Google Scholar
- Pomiankowski AN (1988) The evolution of female mate preferences for male genetic quality. Oxford Surv Evol Biol 5:136–184Google Scholar
- Schauber J, Dorschner RA, Coda AB, Büchau AS, Liu PT, Kiken D, Helfrich YR, Kang S, Elalieh HZ, Steinmeyer A, Zügel U, Bikle DD, Modlin RL, Gallo RL (2007) Injury enhances TLR2 function and antimicrobial peptide expression through a vitamin D-dependent mechanism. J Clinic Inv 117:803–811CrossRefGoogle Scholar
- Sokal RR, Rohlf FJ (1995) Biometry. Freeman, New YorkGoogle Scholar