title: Candidate Gene Analysis Suggests Untapped Genetic Complexity in Melanin-Based Pigmentation in Birds.
abstract: Studies on melanin-based color variation in a context of natural selection have provided a wealth of information on the link between phenotypic and genetic variation. Here, we evaluated associations between melanic plumage patterns and genetic polymorphism in the Réunion grey white-eye (Zosterops borbonicus), a species in which mutations on MC1R do not seem to play any role in explaining melanic variation. This species exhibits 5 plumage color variants that can be grouped into 3 color forms which occupy discrete geographic regions in the lowlands of Réunion, and a fourth high-elevation form which comprises 2 color morphs (grey and brown) and represents a true color polymorphism. We conducted a comprehensive survey of sequence variation in 96 individuals at a series of 7 candidate genes other than MC1R that have been previously shown to influence melanin-based color patterns in vertebrates, including genes that have rarely been studied in a wild bird species before: POMC, Agouti, TYR, TYRP1, DCT, Corin, and SLC24A5 Of these 7 genes, 2 (Corin and TYRP1) displayed an interesting shift in allele frequencies between lowland and highland forms and a departure from mutation-drift equilibrium consistent with balancing selection in the polymorphic highland form only. Sequence variation at Agouti, a gene frequently involved in melanin-based pigmentation patterning, was not associated with color forms or morphs. Thus, we suggest that functionally important changes in loci other than those classically studied are involved in the color polymorphism exhibited by the Réunion grey white-eye and possibly many other nonmodel species.
authors.affiliation: From the Laboratoire Évolution et Diversité Biologique (EDB), UMR 5174, Université Paul Sabatier, Toulouse 3-Centre National de la Recherche Scientifique (CNRS)-École Nationale de Formation Agronomique (ENFA), 118 route de Narbonne, F-31062 Toulouse, France (Bourgeois, Bertrand, Delahaie, Cornuault, and Thébaud); Hémisphères, BP 438, 98822 Poindimié, Nouvelle-Calédonie (Duval); and Museo Nacional de Ciencias Naturales, Consejo Superior de Investigaciones Científicas (CSIC), José Gutiérrez Abascal 2, Madrid E-28006, Spain (Milá). yann.x.c.bourgeois@gmail.com.
authors.forename: Yann X C
authors.initials: YX
authors.lastname: Bourgeois
authors.affiliation: From the Laboratoire Évolution et Diversité Biologique (EDB), UMR 5174, Université Paul Sabatier, Toulouse 3-Centre National de la Recherche Scientifique (CNRS)-École Nationale de Formation Agronomique (ENFA), 118 route de Narbonne, F-31062 Toulouse, France (Bourgeois, Bertrand, Delahaie, Cornuault, and Thébaud); Hémisphères, BP 438, 98822 Poindimié, Nouvelle-Calédonie (Duval); and Museo Nacional de Ciencias Naturales, Consejo Superior de Investigaciones Científicas (CSIC), José Gutiérrez Abascal 2, Madrid E-28006, Spain (Milá).
authors.forename: Joris A M
authors.initials: JA
authors.lastname: Bertrand
authors.affiliation: From the Laboratoire Évolution et Diversité Biologique (EDB), UMR 5174, Université Paul Sabatier, Toulouse 3-Centre National de la Recherche Scientifique (CNRS)-École Nationale de Formation Agronomique (ENFA), 118 route de Narbonne, F-31062 Toulouse, France (Bourgeois, Bertrand, Delahaie, Cornuault, and Thébaud); Hémisphères, BP 438, 98822 Poindimié, Nouvelle-Calédonie (Duval); and Museo Nacional de Ciencias Naturales, Consejo Superior de Investigaciones Científicas (CSIC), José Gutiérrez Abascal 2, Madrid E-28006, Spain (Milá).
authors.forename: Boris
authors.initials: B
authors.lastname: Delahaie
authors.affiliation: From the Laboratoire Évolution et Diversité Biologique (EDB), UMR 5174, Université Paul Sabatier, Toulouse 3-Centre National de la Recherche Scientifique (CNRS)-École Nationale de Formation Agronomique (ENFA), 118 route de Narbonne, F-31062 Toulouse, France (Bourgeois, Bertrand, Delahaie, Cornuault, and Thébaud); Hémisphères, BP 438, 98822 Poindimié, Nouvelle-Calédonie (Duval); and Museo Nacional de Ciencias Naturales, Consejo Superior de Investigaciones Científicas (CSIC), José Gutiérrez Abascal 2, Madrid E-28006, Spain (Milá).
authors.forename: Josselin
authors.initials: J
authors.lastname: Cornuault
authors.affiliation: From the Laboratoire Évolution et Diversité Biologique (EDB), UMR 5174, Université Paul Sabatier, Toulouse 3-Centre National de la Recherche Scientifique (CNRS)-École Nationale de Formation Agronomique (ENFA), 118 route de Narbonne, F-31062 Toulouse, France (Bourgeois, Bertrand, Delahaie, Cornuault, and Thébaud); Hémisphères, BP 438, 98822 Poindimié, Nouvelle-Calédonie (Duval); and Museo Nacional de Ciencias Naturales, Consejo Superior de Investigaciones Científicas (CSIC), José Gutiérrez Abascal 2, Madrid E-28006, Spain (Milá).
authors.forename: Thomas
authors.initials: T
authors.lastname: Duval
authors.affiliation: From the Laboratoire Évolution et Diversité Biologique (EDB), UMR 5174, Université Paul Sabatier, Toulouse 3-Centre National de la Recherche Scientifique (CNRS)-École Nationale de Formation Agronomique (ENFA), 118 route de Narbonne, F-31062 Toulouse, France (Bourgeois, Bertrand, Delahaie, Cornuault, and Thébaud); Hémisphères, BP 438, 98822 Poindimié, Nouvelle-Calédonie (Duval); and Museo Nacional de Ciencias Naturales, Consejo Superior de Investigaciones Científicas (CSIC), José Gutiérrez Abascal 2, Madrid E-28006, Spain (Milá).
authors.forename: Borja
authors.initials: B
authors.lastname: Milá
authors.affiliation: From the Laboratoire Évolution et Diversité Biologique (EDB), UMR 5174, Université Paul Sabatier, Toulouse 3-Centre National de la Recherche Scientifique (CNRS)-École Nationale de Formation Agronomique (ENFA), 118 route de Narbonne, F-31062 Toulouse, France (Bourgeois, Bertrand, Delahaie, Cornuault, and Thébaud); Hémisphères, BP 438, 98822 Poindimié, Nouvelle-Calédonie (Duval); and Museo Nacional de Ciencias Naturales, Consejo Superior de Investigaciones Científicas (CSIC), José Gutiérrez Abascal 2, Madrid E-28006, Spain (Milá).
authors.forename: Christophe
authors.initials: C
authors.lastname: Thébaud
mesh_terms: D000483:Alleles; D000818:Animals; D001717:Birds / Q000235:genetics* / Q000378:metabolism*; D005241:Feathers; D005787:Gene Frequency; D056726:Genetic Association Studies; D014644:Genetic Variation; D008543:Melanins / Q000378:metabolism*; D010858:Pigmentation / Q000235:genetics*; D010860:Pigments, Biological / Q000235:genetics / Q000378:metabolism; D012641:Selection, Genetic
chemical_list: D008543:Melanins; D010860:Pigments, Biological
keywords: Agouti; Corin; TYRP1; Zosterops; melanin pigments; plumage color