title: The crest phenotype in chicken is associated with ectopic expression of HOXC8 in cranial skin.
abstract: The Crest phenotype is characterised by a tuft of elongated feathers atop the head. A similar phenotype is also seen in several wild bird species. Crest shows an autosomal incompletely dominant mode of inheritance and is associated with cerebral hernia. Here we show, using linkage analysis and genome-wide association, that Crest is located on the E22C19W28 linkage group and that it shows complete association to the HOXC-cluster on this chromosome. Expression analysis of tissues from Crested and non-crested chickens, representing 26 different breeds, revealed that HOXC8, but not HOXC12 or HOXC13, showed ectopic expression in cranial skin during embryonic development. We propose that Crest is caused by a cis-acting regulatory mutation underlying the ectopic expression of HOXC8. However, the identification of the causative mutation(s) has to await until a method becomes available for assembling this chromosomal region. Crest is unfortunately located in a genomic region that has so far defied all attempts to establish a contiguous sequence.
authors.affiliation: State Key Laboratory for Agrobiotechnology, China Agricultural University, Beijing, China.
authors.forename: Yanqiang
authors.initials: Y
authors.lastname: Wang
authors.forename: Yu
authors.initials: Y
authors.lastname: Gao
authors.forename: Freyja
authors.initials: F
authors.lastname: Imsland
authors.forename: Xiaorong
authors.initials: X
authors.lastname: Gu
authors.forename: Chungang
authors.initials: C
authors.lastname: Feng
authors.forename: Ranran
authors.initials: R
authors.lastname: Liu
authors.forename: Chi
authors.initials: C
authors.lastname: Song
authors.forename: Michèle
authors.initials: M
authors.lastname: Tixier-Boichard
authors.forename: David
authors.initials: D
authors.lastname: Gourichon
authors.forename: Qingyuan
authors.initials: Q
authors.lastname: Li
authors.forename: Kuanwei
authors.initials: K
authors.lastname: Chen
authors.forename: Huifang
authors.initials: H
authors.lastname: Li
authors.forename: Leif
authors.initials: L
authors.lastname: Andersson
authors.forename: Xiaoxiang
authors.initials: X
authors.lastname: Hu
authors.forename: Ning
authors.initials: N
authors.lastname: Li
mesh_terms: D000818:Animals; D002645:Chickens; D005241:Feathers / Q000033:anatomy & histology* / Q000378:metabolism*; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000235:genetics / Q000502:physiology; D055106:Genome-Wide Association Study; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D008297:Male; D010641:Phenotype; D012867:Skin / Q000378:metabolism*
chemical_list: D018398:Homeodomain Proteins