Identification of the yellow skin gene reveals a hybrid origin of the domestic chicken.
Yellow skin is an abundant phenotype among domestic chickens and is caused by a recessive allele (W*Y) that allows deposition of yellow carotenoids in the skin. Here we show that yellow skin is caused by one or more cis-acting and tissue-specific regulatory mutation(s) that inhibit expression of BCDO2 (beta-carotene dioxygenase 2) in skin. Our data imply that carotenoids are taken up from the circulation in both genotypes but are degraded by BCDO2 in skin from animals carrying the white skin allele (W*W). Surprisingly, our results demonstrate that yellow skin does not originate from the red junglefowl (Gallus gallus), the presumed sole wild ancestor of the domestic chicken, but most likely from the closely related grey junglefowl (Gallus sonneratii). This is the first conclusive evidence for a hybrid origin of the domestic chicken, and it has important implications for our views of the domestication process.
Eriksson
Jonas
J
Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.
Larson
Greger
G
Gunnarsson
Ulrika
U
Bed'hom
Bertrand
B
Tixier-Boichard
Michele
M
Strömstedt
Lina
L
Wright
Dominic
D
Jungerius
Annemieke
A
Vereijken
Addie
A
Randi
Ettore
E
Jensen
Per
P
Andersson
Leif
L
D000483:Alleles; D000818:Animals; D002645:Chickens / Q000235:genetics* / Q000378:metabolism; D004272:DNA, Mitochondrial / Q000235:genetics; D005260:Female; D005808:Genes, Recessive; D006824:Hybridization, Genetic; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D010802:Phylogeny; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci; D012880:Skin Pigmentation / Q000235:genetics* / Q000502:physiology; D050559:beta-Carotene 15,15'-Monooxygenase / Q000235:genetics / Q000378:metabolism
D004272:DNA, Mitochondrial; D050559:beta-Carotene 15,15'-Monooxygenase