title: The size of a melanin-based plumage ornament correlates with glucocorticoid receptor concentrations in the skin of that ornament.
abstract: 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.
authors.affiliation: Department of Biology, Tufts University, Medford, MA 02155, USA. christine.lattin@tufts.edu
authors.forename: Christine R
authors.initials: CR
authors.lastname: Lattin
authors.forename: L Michael
authors.initials: LM
authors.lastname: Romero
mesh_terms: D000818:Animals; D003116:Color; D005241:Feathers; D008297:Male; D008543:Melanins / Q000378:metabolism*; D011965:Receptors, Glucocorticoid / Q000378:metabolism*; D012867:Skin / Q000378:metabolism*; D046370:Sparrows
chemical_list: D008543:Melanins; D011965:Receptors, Glucocorticoid
keywords: Passer domesticus; corticosterone; house sparrow; hypothalamus–pituitary–adrenal axis; plumage signal
references.citation: J Clin Endocrinol Metab. 1997 May;82(5):1345-52
references.pmid: 9141514
references.citation: Trends Ecol Evol. 2008 Sep;23(9):502-10
references.pmid: 18644658
references.citation: Annu Rev Physiol. 1989;51:715-26
references.pmid: 2653201
references.citation: Trends Ecol Evol. 2008 Oct;23(10):532-4
references.pmid: 18715672
references.citation: Br J Dermatol. 1996 May;134(5):837-42
references.pmid: 8736322
references.citation: Am J Physiol Regul Integr Comp Physiol. 2003 Sep;285(3):R594-600
references.pmid: 12791587
references.citation: Br Med J. 1963 Oct 12;2(5362):887-91
references.pmid: 14067675
references.citation: Gen Comp Endocrinol. 2012 Sep 15;178(3):494-501
references.pmid: 22841762
references.citation: Endocrinology. 1974 Apr;94(4):998-1002
references.pmid: 4362047
references.citation: Heart Fail Rev. 2005 Jan;10(1):15-22
references.pmid: 15947887
references.citation: Gen Comp Endocrinol. 2010 Jan 1;165(1):83-90
references.pmid: 19524581
references.citation: Dermatology. 2005;211(3):199-208
references.pmid: 16205064
references.citation: Endocr Rev. 2000 Feb;21(1):55-89
references.pmid: 10696570
references.citation: J Appl Physiol (1985). 2006 May;100(5):1483-8
references.pmid: 16357069
references.citation: Brain Res. 1983 Dec 19;289(1-2):235-40
references.pmid: 6661643
references.citation: J Neuroendocrinol. 2001 May;13(5):412-20
references.pmid: 11328450
references.citation: Gen Comp Endocrinol. 2006 Sep 1;148(2):132-49
references.pmid: 16624311
references.citation: Dev Neurobiol. 2010 Nov;70(13):853-61
references.pmid: 20629050
references.citation: Arch Dermatol Res. 1996 Mar;288(3):140-6
references.pmid: 8967782
references.citation: Gen Comp Endocrinol. 2012 Nov 1;179(2):214-20
references.pmid: 22926326
references.citation: Horm Behav. 2010 Nov;58(5):936-42
references.pmid: 20851701
references.citation: J Steroid Biochem Mol Biol. 1990 Nov 20;37(3):387-94
references.pmid: 2257242
references.citation: Am J Pathol. 2007 Sep;171(3):846-60
references.pmid: 17675581
references.citation: Pigment Cell Melanoma Res. 2008 Apr;21(2):133-8
references.pmid: 18426406
references.citation: Proc Biol Sci. 2013 Feb 13;280(1756):20123033
references.pmid: 23407837