title: Evolution of vertebrate interferon inducible transmembrane proteins.
abstract: BACKGROUND
  Interferon inducible transmembrane proteins (IFITMs) have diverse roles, including the control of cell proliferation, promotion of homotypic cell adhesion, protection against viral infection, promotion of bone matrix maturation and mineralisation, and mediating germ cell development. Most IFITMs have been well characterised in human and mouse but little published data exists for other animals. This study characterised IFITMs in two distantly related marsupial species, the Australian tammar wallaby and the South American grey short-tailed opossum, and analysed the phylogeny of the IFITM family in vertebrates.
  
  
  RESULTS
  Five IFITM paralogues were identified in both the tammar and opossum. As in eutherians, most marsupial IFITM genes exist within a cluster, contain two exons and encode proteins with two transmembrane domains. Only two IFITM genes, IFITM5 and IFITM10, have orthologues in both marsupials and eutherians. IFITM5 arose in bony fish and IFITM10 in tetrapods. The bone-specific expression of IFITM5 appears to be restricted to therian mammals, suggesting that its specialised role in bone production is a recent adaptation specific to mammals. IFITM10 is the most highly conserved IFITM, sharing at least 85% amino acid identity between birds, reptiles and mammals and suggesting an important role for this presently uncharacterised protein.
  
  
  CONCLUSIONS
  Like eutherians, marsupials also have multiple IFITM genes that exist in a gene cluster. The differing expression patterns for many of the paralogues, together with poor sequence conservation between species, suggests that IFITM genes have acquired many different roles during vertebrate evolution.
authors.affiliation: ARC Centre of Excellence for Kangaroo Genomics, Department of Zoology, The University of Melbourne, Victoria, 3010, Australia. hickford@unimelb.edu.au
authors.forename: Danielle
authors.initials: D
authors.lastname: Hickford
authors.forename: Stephen
authors.initials: S
authors.lastname: Frankenberg
authors.forename: Geoff
authors.initials: G
authors.lastname: Shaw
authors.forename: Marilyn B
authors.initials: MB
authors.lastname: Renfree
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017124:Conserved Sequence / Q000235:genetics; D004622:Embryo, Mammalian / Q000187:drug effects / Q000378:metabolism; D019143:Evolution, Molecular; D005333:Fetus / Q000187:drug effects / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007372:Interferons / Q000494:pharmacology*; D007614:Macropodidae / Q000196:embryology / Q000235:genetics*; D008297:Male; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008957:Models, Genetic; D008969:Molecular Sequence Data; D048309:Monodelphis / Q000235:genetics*; D005810:Multigene Family / Q000235:genetics; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid
chemical_list: D008565:Membrane Proteins; D007372:Interferons