Maternal immune factors and the evolution of secondary sexual characters
AbstractSecondary sexual characters have been hypothesized to reveal the ability of males to resist debilitating parasites. Although such reliable signaling of parasite resistance may be maintained by parasite--host coevolution, maternal effects potentially provide a previously neglected factor that could affect the level of genetic variation in resistance to parasites. That could be the case because maternal effects have an entirely environmental basis, or because they can maintain considerable amounts of genetic variation through epistatic effects, even in the presence of strong directional selection. Maternal effects have been shown to occur as maternal allocation of immune factors to offspring, and such allocation may depend on the mating prospects of sons, causing mothers to differentially allocate maternal effects to eggs in species subject to intense sexual selection. Here we show that a maternal effect through innate antibacterial immune defense, lysozyme, which is transferred from the mother to the egg in birds, is positively associated with the evolution of secondary sexual characters. Previous studies have shown that females differentially allocate lysozyme to their eggs when mated to attractive males, and elevated levels of lysozyme are associated with reduced hatching failure and superior health among neonates and adults. In this study, comparative analyses of lysozyme from eggs of 85 species of birds showed a strong positive relationship between brightness of male plumage and egg lysozyme, even when controlling for potentially confounding variables. These findings suggest that maternal immune factors may play a role in the evolution of secondary sexual characters. Copyright 2007, Oxford University Press.
Download InfoIf you experience problems downloading a file, check if you have the proper application to view it first. In case of further problems read the IDEAS help page. Note that these files are not on the IDEAS site. Please be patient as the files may be large.
As the access to this document is restricted, you may want to look for a different version under "Related research" (further below) or search for a different version of it.
Bibliographic InfoArticle provided by International Society for Behavioral Ecology in its journal Behavioral Ecology.
Volume (Year): 18 (2007)
Issue (Month): 3 ()
Contact details of provider:
Postal: Oxford University Press, Great Clarendon Street, Oxford OX2 6DP, UK
Fax: 01865 267 985
Web page: http://beheco.oxfordjournals.org/
You can help add them by filling out this form.
reading list or among the top items on IDEAS.Access and download statisticsgeneral information about how to correct material in RePEc.
For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (Oxford University Press) or (Christopher F. Baum).
If references are entirely missing, you can add them using this form.