title: The Dominant white, Dun and Smoky color variants in chicken are associated with insertion/deletion polymorphisms in the PMEL17 gene.
abstract: Dominant white, Dun, and Smoky are alleles at the Dominant white locus, which is one of the major loci affecting plumage color in the domestic chicken. Both Dominant white and Dun inhibit the expression of black eumelanin. Smoky arose in a White Leghorn homozygous for Dominant white and partially restores pigmentation. PMEL17 encodes a melanocyte-specific protein and was identified as a positional candidate gene due to its role in the development of eumelanosomes. Linkage analysis of PMEL17 and Dominant white using a red jungle fowl/White Leghorn intercross revealed no recombination between these loci. Sequence analysis showed that the Dominant white allele was exclusively associated with a 9-bp insertion in exon 10, leading to an insertion of three amino acids in the PMEL17 transmembrane region. Similarly, a deletion of five amino acids in the transmembrane region occurs in the protein encoded by Dun. The Smoky allele shared the 9-bp insertion in exon 10 with Dominant white, as expected from its origin, but also had a deletion of 12 nucleotides in exon 6, eliminating four amino acids from the mature protein. These mutations are, together with the recessive silver mutation in the mouse, the only PMEL17 mutations with phenotypic effects that have been described so far in any species.
authors.affiliation: Department of Medical Biochemistry and Microbiology, Uppsala University, SE-751 24 Uppsala, Sweden.
authors.forename: Susanne
authors.initials: S
authors.lastname: Kerje
authors.forename: Preety
authors.initials: P
authors.lastname: Sharma
authors.forename: Ulrika
authors.initials: U
authors.lastname: Gunnarsson
authors.forename: Hyun
authors.initials: H
authors.lastname: Kim
authors.forename: Sonchita
authors.initials: S
authors.lastname: Bagchi
authors.forename: Robert
authors.initials: R
authors.lastname: Fredriksson
authors.forename: Karin
authors.initials: K
authors.lastname: Schütz
authors.forename: Per
authors.initials: P
authors.lastname: Jensen
authors.forename: Gunnar
authors.initials: G
authors.lastname: von Heijne
authors.forename: Ron
authors.initials: R
authors.lastname: Okimoto
authors.forename: Leif
authors.initials: L
authors.lastname: Andersson
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002645:Chickens / Q000235:genetics* / Q000378:metabolism; D005241:Feathers / Q000378:metabolism*; D005260:Female; D008040:Genetic Linkage; D008297:Male; D008562:Membrane Glycoproteins; D008861:Microsomes / Q000378:metabolism; D008969:Molecular Sequence Data; D010858:Pigmentation / Q000235:genetics* / Q000502:physiology; D011110:Polymorphism, Genetic; D017433:Protein Structure, Secondary; D011506:Proteins / Q000235:genetics* / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D058951:gp100 Melanoma Antigen
chemical_list: D008562:Membrane Glycoproteins; C548642:Pmel protein, mouse; D011506:Proteins; D058951:gp100 Melanoma Antigen