The dark brown plumage color in chickens is caused by an 8.3 kb deletion upstream of SOX10

Ulrika U. Gunnarsson (1) , Susanne S. Kerje (1) , Bertrand B. Bed'Hom (2) , Anna-Stina A.-S. Sahlqvist (3) , Olov O. Ekwall (3, 4) , Michèle Tixier-Boichard (2) , Olle O. Kämpe (3) , Leif L. Andersson (1, 5)

1 Department of Medical Biochemistry and Microbiology
2 GABI - Génétique Animale et Biologie Intégrative
3 Department of Medical Sciences
4 Department of Rheumatology and Inflammation Research
5 Department of Animal Bredding and Genetics

The Dark brown (DB) mutation in chickens reduces expression of black eumelanin and enhances expression of red pheomelanin, but only in certain parts of the plumage. Here, we present genetic evidence that an 8.3-kb deletion upstream of the SOX10 transcription start site is the causal mutation underlying the DB phenotype. The SOX10 transcription factor has a well-established role in melanocyte biology and is essential for melanocyte migration and survival. Previous studies have demonstrated that the mouse homolog of a highly conserved element within the deleted region is a SOX10 enhancer. The mechanism of action of this mutation remains to be established, but one possible scenario is that the deletion leads to reduced SOX10 expression which in turn down-regulates expression of key enzymes in pigment synthesis such as tyrosinase. Lower tyrosinase activity leads to a shift toward a more pheomelanistic (reddish) plumage color, which is the characteristic feature of the DB phenotype.

Mots clés: chicken; plumage color; sox10; regulatory mutation; deletion

Domaines: Sciences agricoles

Ulrika U. Gunnarsson, Susanne S. Kerje, Bertrand B. Bed'Hom, Anna-Stina A.-S. Sahlqvist, Olov O. Ekwall, et al.. The dark brown plumage color in chickens is caused by an 8.3 kb deletion upstream of SOX10. Pigment Cell Melanoma Research, 2011, 24 (2), pp.268-274. ⟨10.1111/j.1755-148X.2011.00825.x⟩. ⟨hal-01000175⟩