Open Access

A first genotyping assay of French cattle breeds based on a new allele of the extension gene encoding the melanocortin-1 receptor (Mc1r)

  • François Rouzaud1,
  • Juliette Martin1,
  • Paul François Gallet1,
  • Didier Delourme1,
  • Valérie Goulemot-Leger3,
  • Yves Amigues3,
  • François Ménissier4,
  • Hubert Levéziel1, 2,
  • Raymond Julien1 and
  • Ahmad Oulmouden1Email author
Genetics Selection Evolution200032:511

Received: 21 February 2000

Accepted: 6 June 2000

Published: 15 September 2000


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, α-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 ED 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.


cattlegenotypingcoat colorextensionpolymorphism

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Authors’ Affiliations

Unité de génétique moléculaire animale, UMR 1061 (Université/INRA), Université de Limoges
Unité de génétique biochimique et cytogénétique, UR339, Institut national de la recherche agronomique
Laboratoire d'analyses génétiques pour les espèces animales (LABOGENA), Institut national de la recherche agronomique
Station de génétique quantitative et appliquée, UR337, Institut national de la recherche agronomique


© INRA, EDP Sciences 2000