title: The melanocortin system regulates body pigmentation and social behaviour in a colour polymorphic cichlid fish.
abstract: The melanocortin system is a neuroendocrine system that regulates a range of physiological and behavioural processes. We examined the extent to which the melanocortin system simultaneously regulates colour and behaviour in the cichlid fishAstatotilapia burtoniWe found that yellow males are more aggressive than blue males, in line with previous studies. We then found that exogenous α-melanocyte-stimulating hormone (α-MSH) increases yellowness of the body and dispersal of xanthophore pigments in both morphs. However, α-MSH had a morph-specific effect on aggression, with only blue males showing an increase in the rate of aggression. Exogenous agouti signalling peptide (ASIP), a melanocortin antagonist, did not affect coloration but reduced the rate of aggression in both colour morphs. Blue males had higher cortisol levels than yellow males. Neural gene expression of melanocortin receptors (mcr) and ligands was not differentially regulated between colour morphs. In the skin, however,mc1rand pro-opiomelanocortin (pomc)βwere upregulated in blue males, whileasip 1was upregulated in yellow males. The effects of α-MSH on behaviour and body coloration, combined with morph-specific regulation of the stress response and the melanocortin system, suggest that the melanocortin system contributes to the polymorphism in behaviour and coloration inA. burtoni.
authors.affiliation: Department of Integrative Biology, The University of Texas at Austin, Austin, TX 78712, USA dijks1p@cmich.edu.|Behavioural Biology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands.|Department of Biology, Central Michigan University, Mount Pleasant, MI 48859, USA.
authors.forename: Peter D
authors.identifier: http://orcid.org/0000-0001-5382-225X
authors.initials: PD
authors.lastname: Dijkstra
authors.affiliation: Department of Integrative Biology, The University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Sean M
authors.initials: SM
authors.lastname: Maguire
authors.affiliation: Department of Integrative Biology, The University of Texas at Austin, Austin, TX 78712, USA.|Institute for Cellular & Molecular Biology, The University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Rayna M
authors.initials: RM
authors.lastname: Harris
authors.affiliation: Department of Integrative Biology, The University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Agosto A
authors.initials: AA
authors.lastname: Rodriguez
authors.affiliation: Program for Ecology, Evolution and Conservation Biology, Beckman Institute, University of Illinois at Urbana-Champaign, 405 N. Mathews Avenue, Urbana, IL 61801, USA.
authors.forename: Ross S
authors.initials: RS
authors.lastname: DeAngelis
authors.affiliation: Department of Integrative Biology, The University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Flores
authors.affiliation: Department of Integrative Biology, The University of Texas at Austin, Austin, TX 78712, USA.|Institute for Cellular & Molecular Biology, The University of Texas at Austin, Austin, TX 78712, USA.|Institute for Neuroscience, The University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Hans A
authors.initials: HA
authors.lastname: Hofmann
mesh_terms: D000374:Aggression; D000818:Animals; D001522:Behavior, Animal; D023681:Cichlids / Q000502:physiology*; D003116:Color; D029941:Fish Proteins / Q000502:physiology; D008297:Male; D053486:Melanocortins / Q000502:physiology*; D010858:Pigmentation; D011333:Pro-Opiomelanocortin / Q000502:physiology; D044101:Receptors, Melanocortin / Q000502:physiology*; D012919:Social Behavior
chemical_list: D029941:Fish Proteins; D053486:Melanocortins; D044101:Receptors, Melanocortin; D011333:Pro-Opiomelanocortin
keywords: fish; hormones; male–male competition; melanocortin receptors; pigmentation; stress