title: Endogenous retrovirus EAV-HP linked to blue egg phenotype in Mapuche fowl.
abstract: Oocyan or blue/green eggshell colour is an autosomal dominant trait found in native chickens (Mapuche fowl) of Chile and in some of their descendants in European and North American modern breeds. We report here the identification of an endogenous avian retroviral (EAV-HP) insertion in oocyan Mapuche fowl and European breeds. Sequencing data reveals 100% retroviral identity between the Mapuche and European insertions. Quantitative real-time PCR analysis of European oocyan chicken indicates over-expression of the SLCO1B3 gene (P<0.05) in the shell gland and oviduct. Predicted transcription factor binding sites in the long terminal repeats (LTR) indicate AhR/Ar, a modulator of oestrogen, as a possible promoter/enhancer leading to reproductive tissue-specific over-expression of the SLCO1B3 gene. Analysis of all jungle fowl species Gallus sp. supports the retroviral insertion to be a post-domestication event, while identical LTR sequences within domestic chickens are in agreement with a recent de novo mutation.
authors.affiliation: Centre for Genetics and Genomics, School of Biology, University of Nottingham, University Park, Nottingham, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Wragg
authors.forename: Joram M
authors.initials: JM
authors.lastname: Mwacharo
authors.forename: José A
authors.initials: JA
authors.lastname: Alcalde
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
authors.forename: Jian-Lin
authors.initials: JL
authors.lastname: Han
authors.forename: Jaime
authors.initials: J
authors.lastname: Gongora
authors.forename: David
authors.initials: D
authors.lastname: Gourichon
authors.forename: Michèle
authors.initials: M
authors.lastname: Tixier-Boichard
authors.forename: Olivier
authors.initials: O
authors.lastname: Hanotte
mesh_terms: D000818:Animals; D030161:Avian Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D002645:Chickens / Q000821:virology*; D002677:Chile; D002874:Chromosome Mapping; D004528:Egg Shell / Q000378:metabolism*; D020077:Endogenous Retroviruses / Q000235:genetics*; D005260:Female; D005786:Gene Expression Regulation; D006720:Homozygote; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation; D029362:Organic Anion Transporters, Sodium-Independent / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D010802:Phylogeny; D010858:Pigmentation / Q000235:genetics*; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D020079:Terminal Repeat Sequences
chemical_list: D030161:Avian Proteins; D029362:Organic Anion Transporters, Sodium-Independent