title: The Dark brown plumage color in chickens is caused by an 8.3-kb deletion upstream of SOX10.
abstract: 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.
authors.affiliation: Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.
authors.forename: Ulrika
authors.initials: U
authors.lastname: Gunnarsson
authors.forename: Susanne
authors.initials: S
authors.lastname: Kerje
authors.forename: Bertrand
authors.initials: B
authors.lastname: Bed'hom
authors.forename: Anna-Stina
authors.initials: AS
authors.lastname: Sahlqvist
authors.forename: Olov
authors.initials: O
authors.lastname: Ekwall
authors.forename: Michele
authors.initials: M
authors.lastname: Tixier-Boichard
authors.forename: Olle
authors.initials: O
authors.lastname: Kämpe
authors.forename: Leif
authors.initials: L
authors.lastname: Andersson
mesh_terms: D000818:Animals; D002645:Chickens / Q000033:anatomy & histology / Q000235:genetics*; D003116:Color; D005241:Feathers; D005260:Female; D017353:Gene Deletion; D005786:Gene Expression Regulation; D008040:Genetic Linkage; D008297:Male; D008543:Melanins / Q000235:genetics; D014442:Monophenol Monooxygenase / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D010641:Phenotype; D010858:Pigmentation / Q000502:physiology*; D012045:Regulatory Sequences, Nucleic Acid; D055757:SOXE Transcription Factors / Q000235:genetics*
chemical_list: D008543:Melanins; D055757:SOXE Transcription Factors; C018362:pheomelanin; C041877:eumelanin; D014442:Monophenol Monooxygenase