title: Identification of an additional two-cysteine containing type I interferon in rainbow trout Oncorhynchus mykiss provides evidence of a major gene duplication event within this gene family in teleosts.
abstract: Multiple type I interferons (IFNs) have recently been identified in salmonids, containing two or four conserved cysteines. In this work, a novel two-cysteine containing (2C) IFN gene was identified in rainbow trout. This novel trout IFN gene (termed IFN5) formed a phylogenetic group that is distinct from the other three salmonid IFN groups sequenced to date and had a close evolutionary relationship with IFNs from advanced fish species. Our data demonstrate that two subgroups are apparent within each of the 2C and 4C type I IFNs, an evolutionary outcome possibly due to two rounds of genome duplication events that have occurred within teleosts. We have examined gene expression of the trout 2C type I IFN in cultured cells following stimulation with lipopolysaccharide, phytohaemagglutinin, polyI:C or recombinant IFN, or after transfection with polyI:C. The kinetics of gene expression was also studied after viral infection. Analysis of the regulatory elements in the IFN promoter region predicted several binding sites for key transcription factors that potentially play an important role in mediating IFN5 gene expression.
authors.affiliation: Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Aberdeen, UK.
authors.forename: Mingxian
authors.initials: M
authors.lastname: Chang
authors.forename: Pin
authors.initials: P
authors.lastname: Nie
authors.forename: Bertrand
authors.initials: B
authors.lastname: Collet
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Secombes
authors.forename: Jun
authors.initials: J
authors.lastname: Zou
mesh_terms: D000818:Animals; D003545:Cysteine / Q000235:genetics; D029941:Fish Proteins / Q000235:genetics / Q000276:immunology*; D020440:Gene Duplication; D007370:Interferon Type I / Q000235:genetics* / Q000276:immunology*; D017686:Oncorhynchus mykiss / Q000235:genetics* / Q000276:immunology*; D012330:RNA, Double-Stranded / Q000276:immunology
chemical_list: D029941:Fish Proteins; D007370:Interferon Type I; D012330:RNA, Double-Stranded; D003545:Cysteine