title: A first genotyping assay of French cattle breeds based on a new allele of the extension gene encoding the melanocortin-1 receptor (Mc1r).
abstract: The seven transmembrane domain melanocortin-1 receptor (Mc1r) encoded by the coat color extension gene (E) plays a key role in the signaling pathway of melanin synthesis. Upon the binding of agonist (melanocortin hormone, alpha-MSH) or antagonist (Agouti protein) ligands, the melanosomal synthesis of eumelanin and/or phaeomelanin pigments is stimulated or inhibited, respectively. Different alleles of the extension gene were cloned from unrelated animals belonging to French cattle breeds and sequenced. The wild type E allele was mainly present in Normande cattle, the dominant E(D) allele in animals with black color (i.e. Holstein), whereas the recessive e allele was identified in homozygous animals exhibiting a more or less strong red coat color (Blonde d'Aquitaine, Charolaise, Limousine and Salers). A new allele, named E1, was found in either homozygous (E1/E1) or heterozygous (E1/E) individuals in Aubrac and Gasconne breeds. This allele displayed a 4 amino acid duplication (12 nucleotides) located within the third cytoplasmic loop of the receptor, a region known to interact with G proteins. A first genotyping assay of the main French cattle breeds is described based on these four extension alleles.
authors.affiliation: Unité de génétique moléculaire animale, UMR 1061 (Université/INRA), Université de Limoges, 87060 Limoges Cedex, France.
authors.forename: F
authors.initials: F
authors.lastname: Rouzaud
authors.forename: J
authors.initials: J
authors.lastname: Martin
authors.forename: P F
authors.initials: PF
authors.lastname: Gallet
authors.forename: D
authors.initials: D
authors.lastname: Delourme
authors.forename: V
authors.initials: V
authors.lastname: Goulemot-Leger
authors.forename: Y
authors.initials: Y
authors.lastname: Amigues
authors.forename: F
authors.initials: F
authors.lastname: Ménissier
authors.forename: H
authors.initials: H
authors.lastname: Levéziel
authors.forename: R
authors.initials: R
authors.lastname: Julien
authors.forename: A
authors.initials: A
authors.lastname: Oulmouden