Faculty Opinions recommendation of Intracellular glucocorticoid receptors in spleen, but not skin, vary seasonally in wild house sparrows (Passer domesticus).

Author(s):  
Ellen D Ketterson ◽  
Mark Peterson
2013 ◽  
Vol 9 (5) ◽  
pp. 20130440 ◽  
Author(s):  
Christine R. Lattin ◽  
L. Michael Romero

Glucocorticoid hormones such as corticosterone (CORT) play crucial roles in many physiological processes. CORT's actions are primarily mediated via binding to two receptors (glucocorticoid receptors (GRs) and mineralocorticoid receptors (MRs)) in different target tissues. CORT receptors can be independently regulated from circulating hormone titres, from tissue to tissue and even within different regions of the same tissue type. Increasing evidence has shown relationships between circulating CORT and melanin-based pigmentation in skin and feathers, yet to our knowledge, there have been no studies of CORT receptors in the skin of melanized ornaments. Male house sparrows ( Passer domesticus ) have a black, melanized bib, and evidence suggests that bib size is an important intraspecific signal. We examined the relationship between bib area and tissue sensitivity to CORT by quantifying GR and MR in bib skin and in adjacent paler-feathered belly skin (as a control tissue) at different life-history stages using radioligand binding assays. Males with larger bibs relative to their life-history stage had less GR in bib skin, but not belly skin, than males with smaller bibs. These results suggest a connection between the size of a melanin-based ornament and the underlying tissue's responsiveness to CORT.


2011 ◽  
Vol 279 (1733) ◽  
pp. 1560-1566 ◽  
Author(s):  
Lee Koren ◽  
Shinichi Nakagawa ◽  
Terry Burke ◽  
Kiran K. Soma ◽  
Katherine E. Wynne-Edwards ◽  
...  

Potential mechanistic mediators of Darwinian fitness, such as stress hormones or sex hormones, have been the focus of many studies. An inverse relationship between fitness and stress or sex hormone concentrations has been widely assumed, although empirical evidence is scarce. Feathers gradually accumulate hormones during their growth and provide a novel way to measure hormone concentrations integrated over time. Using liquid chromatography–tandem mass spectrometry, we measured testosterone, corticosterone and cortisol in the feathers of house sparrows ( Passer domesticus ) in a wild population which is the subject of a long-term study. Although corticosterone is considered the dominant avian glucocorticoid, we unambiguously identified cortisol in feathers. In addition, we found that feathers grown during the post-nuptial moult in autumn contained testosterone, corticosterone and cortisol levels that were significantly higher in birds that subsequently died over the following winter than in birds that survived. Thus, feather steroids are candidate prospective biomarkers to predict the future survival of individuals in the wild.


1973 ◽  
pp. 39-48 ◽  
Author(s):  
Carl J. Mitchell ◽  
Richard O. Hayes

2010 ◽  
Vol 88 (10) ◽  
pp. 1021-1031 ◽  
Author(s):  
L. De Neve ◽  
J. D. Ibañez-Alamo ◽  
M. Soler

Sexual dimorphism and age-related differences are sources that contribute to morphologic and physiologic variation within animal populations. Measurement of animal performance may indicate whether this variation is functionally relevant. Our study aimed to experimentally test this statement in a captive population of House Sparrows ( Passer domesticus (L., 1758)) by examining age- and sex-related differences in escape response and its relationship to several morphological (tarsus, wing, tail lengths, and body mass) and physiological traits (cell-mediated immunity, natural antibodies, complement activity, hematocrit, and stress response). Escape response from a predator is considered a good variable to measure animal performance, because natural selection clearly favours individuals that avoid predators successfully. Our experimental design also aimed to standardize possible confounding factors affecting escape behaviour under natural conditions. We exposed sparrows to short episodes of high predation risk by simulating the attack of a predator and assumed that the capture order of individuals was related to their escape capacity. The optimal strategy was the immediate escape response for all individuals. We found that first-year males were the best escapers. In support of the hypothesis, juvenile males gathered a better optimum of several morphological and physiological characters that related to capture order.


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