title: Strain-specific copy number variation in the intelectin locus on the 129 mouse chromosome 1.
abstract: BACKGROUND
  C57BL/6J mice possess a single intelectin (Itln) gene on chromosome 1. The function of intelectins is not well understood, but roles have been postulated in insulin sensitivity, bacterial recognition, intestinal lactoferrin uptake and response to parasites and allergens. In contrast to C57BL/6J mice, there is evidence for expansion of the Itln locus in other strains and at least one additional mouse Itln gene product has been described. The aim of this study was to sequence and characterise the Itln locus in the 129S7 strain, to determine the nature of the chromosomal expansion and to inform possible future gene deletion strategies.
  
  
  RESULTS
  Six 129S7 BAC clones were sequenced and assembled to generate 600 kbp of chromosomal sequence, including the entire Itln locus of approximately 500 kbp. The locus contained six distinct Itln genes, two CD244 genes and several Itln- and CD244-related pseudogenes. It was approximately 433 kbp larger than the corresponding C57BL/6J locus. The expansion of the Itln locus appears to have occurred through multiple duplications of a segment consisting of a full-length Itln gene, a CD244 (pseudo)gene and an Itln pseudogene fragment. Strong evidence for tissue-specific distribution of Itln variants was found, indicating that Itln duplication contributes more than a simple gene dosage effect.
  
  
  CONCLUSIONS
  We have characterised the Itln locus in 129S7 mice to reveal six Itln genes with distinct sequence and expression characteristics. Since C57BL/6J mice possess only a single Itln gene, this is likely to contribute to functional differences between C57BL/6J and other mouse strains.
authors.affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Sciences, University of Edinburgh, Roslin, Midlothian, UK.
authors.forename: Zen H
authors.initials: ZH
authors.lastname: Lu
authors.forename: Alex
authors.initials: A
authors.lastname: di Domenico
authors.forename: Steven H
authors.initials: SH
authors.lastname: Wright
authors.forename: Pamela A
authors.initials: PA
authors.lastname: Knight
authors.forename: C Bruce A
authors.initials: CB
authors.lastname: Whitelaw
authors.forename: Alan D
authors.initials: AD
authors.lastname: Pemberton
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000235:genetics; D001483:Base Sequence; D001665:Binding Sites; D022202:Chromosomes, Artificial, Bacterial; D033481:Chromosomes, Mammalian / Q000235:genetics; D019143:Evolution, Molecular; D018628:Gene Dosage; D015723:Gene Library; D056426:Genetic Loci; D023281:Genomics; D018398:Homeodomain Proteins / Q000378:metabolism; D037102:Lectins / Q000235:genetics*; D051379:Mice; D057507:Mice, 129 Strain; D008810:Mice, Inbred C57BL; D058977:Molecular Sequence Annotation; D008969:Molecular Sequence Data; D010802:Phylogeny; D011401:Promoter Regions, Genetic; D011544:Pseudogenes; D011971:Receptors, Immunologic / Q000235:genetics; D056916:Segmental Duplications, Genomic; D017422:Sequence Analysis, DNA; D000071176:Signaling Lymphocytic Activation Molecule Family; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D015703:Antigens, CD; C490007:Cd244a protein, mouse; D018398:Homeodomain Proteins; D037102:Lectins; C102837:Nkx3-1 protein, mouse; D011971:Receptors, Immunologic; D000071176:Signaling Lymphocytic Activation Molecule Family; D014157:Transcription Factors