title: Expansion of amphibian intronless interferons revises the paradigm for interferon evolution and functional diversity.
abstract: Interferons (IFNs) are key cytokines identified in vertebrates and evolutionary dominance of intronless IFN genes in amniotes is a signature event in IFN evolution. For the first time, we show that the emergence and expansion of intronless IFN genes is evident in amphibians, shown by 24-37 intronless IFN genes in each frog species. Amphibian IFNs represent a molecular complex more complicated than those in other vertebrate species, which revises the established model of IFN evolution to facilitate re-inspection of IFN molecular and functional diversity. We identified these intronless amphibian IFNs and their intron-containing progenitors, and functionally characterized constitutive and inductive expression and antimicrobial roles in infections caused by zoonotic pathogens, such as influenza viruses and Listeria monocytogenes. Amphibians, therefore, may serve as overlooked vectors/hosts for zoonotic pathogens, and the amphibian IFN system provides a model to study IFN evolution in molecular and functional diversity in coping with dramatic environmental changes during terrestrial adaption.
authors.affiliation: Departments of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, USA.
authors.forename: Yongming
authors.initials: Y
authors.lastname: Sang
authors.affiliation: Departments of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, USA.
authors.forename: Qinfang
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, USA.
authors.forename: Jinhwa
authors.initials: J
authors.lastname: Lee
authors.affiliation: Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, USA.|Arthropod-Borne Animal Diseases Research Unit, Center for Grain and Animal Health Research, Agricultural Research Service, United States Department of Agriculture, Manhattan, KS, USA.
authors.forename: Wenjun
authors.initials: W
authors.lastname: Ma
authors.affiliation: Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, USA.|Arthropod-Borne Animal Diseases Research Unit, Center for Grain and Animal Health Research, Agricultural Research Service, United States Department of Agriculture, Manhattan, KS, USA.
authors.forename: D Scott
authors.initials: DS
authors.lastname: McVey
authors.affiliation: Departments of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, USA.
authors.forename: Frank
authors.initials: F
authors.lastname: Blecha
mesh_terms: D000663:Amphibians / Q000235:genetics / Q000276:immunology; D000818:Animals; D019143:Evolution, Molecular; D014644:Genetic Variation; D007372:Interferons / Q000235:genetics* / Q000276:immunology; D007438:Introns / Q000235:genetics* / Q000276:immunology; D008089:Listeria monocytogenes / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity; D005810:Multigene Family / Q000235:genetics; D009975:Orthomyxoviridae / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity; D010802:Phylogeny; D015047:Zoonoses / Q000235:genetics* / Q000821:virology
chemical_list: D007372:Interferons