The size of a melanin-based plumage ornament correlates with glucocorticoid receptor concentrations in the skin of that ornament

Abstract

PhysiologyThe size of a melanin-based plumage ornament correlates with glucocorticoid receptor concentrations in the skin of that ornament Christine R. Lattin and L. Michael Romero Department of Biology, Tufts University, Medford, MA 02155, USA 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 melaninbased 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.

Becoming more like your mate: hormonal similarity reduces divorce rates in a wild songbird

“…Indeed, we found that individuals that separated had higher reproductive success with their new partners the next year, which could also be a result of increased parental experience and/ or age from one breeding season to the next (Bouwhuis, Charmantier, Verhulst, & Sheldon, 2010;Bouwhuis, Sheldon, Verhulst, & Charmantier, 2009). Individuals select mates based on a suite of behavioural and morphological traits, and it is likely that baseline corticosterone levels mediate one or a suite of these sexually selected traits (Almasi, Roulin, & Jenni, 2013;Fairhurst, Dawson, Oort, & Bortolotti, 2014;Lattin & Romero, 2013). For example, baseline corticosterone is positively related to parental care Ouyang, Sharp, et al, 2013), and if individuals select mates based on the ability to provide care, they may also be selecting individuals with high baseline corticosterone levels, which modulate a suite of other behavioural traits (Henderson, Heidinger, Evans, & Arnold, 2013;Lendvai, Giraudeau, N emeth, Bak o, & McGraw, 2013;Saino et al, 2013).…”

“…Individuals select mates based on a suite of behavioural and morphological traits, and it is likely that baseline corticosterone levels mediate one or a suite of these sexually selected traits (Almasi, Roulin, & Jenni, 2013;Fairhurst, Dawson, Oort, & Bortolotti, 2014;Lattin & Romero, 2013). For example, baseline corticosterone is positively related to parental care Ouyang, Sharp, et al, 2013), and if individuals select mates based on the ability to provide care, they may also be selecting individuals with high baseline corticosterone levels, which modulate a suite of other behavioural traits (Henderson, Heidinger, Evans, & Arnold, 2013;Lendvai, Giraudeau, N emeth, Bak o, & McGraw, 2013;Saino et al, 2013). Indeed, in this great tit population, high baseline corticosterone levels during the prebreeding period are indicative of high parental effort during breeding (Ouyang, Muturi, Quetting, & Hau, 2012).…”

Sex‐Specific Associations Between Nest Defence, Exploration and Breathing Rate in Breeding Pied Flycatchers

“…Within-individual variation in behaviour can arise from state dependency of behaviour. In the case of betweenindividual variation, pleiotropic hormone action can furthermore link behaviour to other hormone-mediated traits, such as immunity, (Koolhaas 2008), pigmentation (Ducrest et al 2008;Lattin & Romero 2013) and metabolism (Careau et al 2010(Careau et al , 2011Krams et al 2013a,b), among others. In the case of betweenindividual variation, pleiotropic hormone action can furthermore link behaviour to other hormone-mediated traits, such as immunity, (Koolhaas 2008), pigmentation (Ducrest et al 2008;Lattin & Romero 2013) and metabolism (Careau et al 2010(Careau et al , 2011Krams et al 2013a,b), among others.…”

“…This would, for example, occur when the expression of several behavioural traits is underpinned by a common factor that varies within an individual, such as hunger level (Dingemanse et al 2012). In the case of betweenindividual variation, pleiotropic hormone action can furthermore link behaviour to other hormone-mediated traits, such as immunity, (Koolhaas 2008), pigmentation (Ducrest et al 2008;Lattin & Romero 2013) and metabolism (Careau et al 2010(Careau et al , 2011Krams et al 2013a,b), among others. Associations between physiological markers of stress responsiveness and behaviour have been intensively studied in birds (Carere et al 2003;Kralj-Fiser et al 2010;Atwell et al 2012), which appear increasingly popular model organisms for non-human animal behaviour and personality research (van Oers & Naguib 2013).…”

Proteomic analysis of the skin from Chinese fire-bellied newt and comparison to Chinese giant salamander

“…Tyrosinase as the key regulatory enzyme of melanogenesis played a major role in skin color (Chen et al, 2012). Glucocorticoid receptor was reported to be associated with melanin-based pigmentation in skin (Lattin and Romero, 2013). The results suggest that the species require these highly expressed genes to ensure skin pigmentation.…”