title: Sequence of a complete chicken BG haplotype shows dynamic expansion and contraction of two gene lineages with particular expression patterns.
abstract: Many genes important in immunity are found as multigene families. The butyrophilin genes are members of the B7 family, playing diverse roles in co-regulation and perhaps in antigen presentation. In humans, a fixed number of butyrophilin genes are found in and around the major histocompatibility complex (MHC), and show striking association with particular autoimmune diseases. In chickens, BG genes encode homologues with somewhat different domain organisation. Only a few BG genes have been characterised, one involved in actin-myosin interaction in the intestinal brush border, and another implicated in resistance to viral diseases. We characterise all BG genes in B12 chickens, finding a multigene family organised as tandem repeats in the BG region outside the MHC, a single gene in the MHC (the BF-BL region), and another single gene on a different chromosome. There is a precise cell and tissue expression for each gene, but overall there are two kinds, those expressed by haemopoietic cells and those expressed in tissues (presumably non-haemopoietic cells), correlating with two different kinds of promoters and 5' untranslated regions (5'UTR). However, the multigene family in the BG region contains many hybrid genes, suggesting recombination and/or deletion as major evolutionary forces. We identify BG genes in the chicken whole genome shotgun sequence, as well as by comparison to other haplotypes by fibre fluorescence in situ hybridisation, confirming dynamic expansion and contraction within the BG region. Thus, the BG genes in chickens are undergoing much more rapid evolution compared to their homologues in mammals, for reasons yet to be understood.
authors.affiliation: Basel Institute for Immunology, Basel, Switzerland; Department of Veterinary Disease Biology, University of Copenhagen, Copenhagen, Denmark; Department of International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Jan
authors.initials: J
authors.lastname: Salomonsen
authors.affiliation: Department of Pathology, University of Cambridge, Cambridge, United Kingdom.
authors.forename: John A
authors.initials: JA
authors.lastname: Chattaway
authors.affiliation: Department of Pathology, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Andrew C Y
authors.initials: AC
authors.lastname: Chan
authors.affiliation: Department of Pathology, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Aimée
authors.initials: A
authors.lastname: Parker
authors.affiliation: Department of Pathology, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Samuel
authors.initials: S
authors.lastname: Huguet
authors.affiliation: Pirbright Institute (formerly Institute for Animal Health), Compton, United Kingdom.
authors.forename: Denise A
authors.initials: DA
authors.lastname: Marston
authors.affiliation: Pirbright Institute (formerly Institute for Animal Health), Compton, United Kingdom.
authors.forename: Sally L
authors.initials: SL
authors.lastname: Rogers
authors.affiliation: Pirbright Institute (formerly Institute for Animal Health), Compton, United Kingdom.
authors.forename: Zhiguang
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Pirbright Institute (formerly Institute for Animal Health), Compton, United Kingdom; Department of Zoology, Oxford University, Oxford, United Kingdom.
authors.forename: Adrian L
authors.initials: AL
authors.lastname: Smith
authors.affiliation: Pirbright Institute (formerly Institute for Animal Health), Compton, United Kingdom.
authors.forename: Karen
authors.initials: K
authors.lastname: Staines
authors.affiliation: Pirbright Institute (formerly Institute for Animal Health), Compton, United Kingdom.
authors.forename: Colin
authors.initials: C
authors.lastname: Butter
authors.affiliation: Basel Institute for Immunology, Basel, Switzerland.
authors.forename: Patricia
authors.initials: P
authors.lastname: Riegert
authors.affiliation: Basel Institute for Immunology, Basel, Switzerland; Department of Medical Microbiology, University of Oulu and Nordlab, Oulu, Finland.
authors.forename: Olli
authors.initials: O
authors.lastname: Vainio
authors.affiliation: Department of Veterinary Disease Biology, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Line
authors.initials: L
authors.lastname: Nielsen
authors.affiliation: Institute for Animal Physiology, Department of Veterinary Sciences, Ludwig Maximilians University, Munich, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Kaspers
authors.affiliation: School of Biosciences, University of Kent, Canterbury, United Kingdom.
authors.forename: Darren K
authors.initials: DK
authors.lastname: Griffin
authors.affiliation: Wellcome Trust Sanger Institute, Hinxton, United Kingdom.
authors.forename: Fengtang
authors.initials: F
authors.lastname: Yang
authors.affiliation: Institute for Cellular and Molecular Embryology, CNRS UMR 7128, Nogent-sur-Marne, France; Institute Andre Lwoff, CNRS FRE 2937, Villejuif, France.
authors.forename: Rima
authors.initials: R
authors.lastname: Zoorob
authors.affiliation: Institute Andre Lwoff, CNRS FRE 2937, Villejuif, France.
authors.forename: Francois
authors.initials: F
authors.lastname: Guillemot
authors.affiliation: Institute Andre Lwoff, CNRS FRE 2937, Villejuif, France.
authors.forename: Charles
authors.initials: C
authors.lastname: Auffray
authors.affiliation: Wellcome Trust Sanger Institute, Hinxton, United Kingdom.
authors.forename: Stephan
authors.initials: S
authors.lastname: Beck
authors.affiliation: Basel Institute for Immunology, Basel, Switzerland; Department of Cancer and Inflammation, University of South Denmark, Odense, Denmark.
authors.forename: Karsten
authors.initials: K
authors.lastname: Skjødt
authors.affiliation: Basel Institute for Immunology, Basel, Switzerland; Department of Pathology, University of Cambridge, Cambridge, United Kingdom; Pirbright Institute (formerly Institute for Animal Health), Compton, United Kingdom; Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Jim
authors.initials: J
authors.lastname: Kaufman
mesh_terms: D000818:Animals; D001483:Base Sequence; D001789:Blood Group Antigens / Q000235:genetics*; D000071797:Butyrophilins; D002645:Chickens / Q000097:blood / Q000235:genetics*; D016678:Genome / Q000235:genetics; D006239:Haplotypes / Q000235:genetics; D008285:Major Histocompatibility Complex / Q000235:genetics*; D008562:Membrane Glycoproteins / Q000235:genetics; D005810:Multigene Family / Q000235:genetics; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D020080:Tandem Repeat Sequences / Q000235:genetics
chemical_list: D001789:Blood Group Antigens; D000071797:Butyrophilins; D008562:Membrane Glycoproteins