title: Role of quail in the interspecies transmission of H9 influenza A viruses: molecular changes on HA that correspond to adaptation from ducks to chickens.
abstract: H9 influenza viruses have become endemic in land-based domestic poultry in Asia and have sporadically crossed to pigs and humans. To understand the molecular determinants of their adaptation to land-based birds, we tested the replication and transmission of several 1970s duck H9 viruses in chickens and quail. Quail were more susceptible than chickens to these viruses, and generation of recombinant H9 viruses by reverse genetics showed that changes in the HA gene are sufficient to initiate efficient replication and transmission in quail. Seven amino acid positions on the HA molecule corresponded to adaptation to land-based birds. In quail H9 viruses, the pattern of amino acids at these seven positions is intermediate between those of duck and chicken viruses; this fact may explain the susceptibility of quail to duck H9 viruses. Our findings suggest that quail provide an environment in which the adaptation of influenza viruses from ducks generates novel variants that can cross the species barrier.
authors.affiliation: Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, Tennessee 38105-2794, USA. Daniel.Perez@stjude.org
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Perez
authors.forename: Wilina
authors.initials: W
authors.lastname: Lim
authors.forename: Jon P
authors.initials: JP
authors.lastname: Seiler
authors.forename: Guan
authors.initials: G
authors.lastname: Yi
authors.forename: Malik
authors.initials: M
authors.lastname: Peiris
authors.forename: Kennedy F
authors.initials: KF
authors.lastname: Shortridge
authors.forename: Robert G
authors.initials: RG
authors.lastname: Webster
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D001715:Bird Diseases / Q000635:transmission* / Q000821:virology; D002645:Chickens / Q000821:virology; D004372:Ducks / Q000821:virology; D019143:Evolution, Molecular; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics; D006801:Humans; D009980:Influenza A virus / Q000235:genetics* / Q000502:physiology; D005585:Influenza in Birds / Q000635:transmission / Q000821:virology; D008969:Molecular Sequence Data; D010802:Phylogeny; D011201:Poultry Diseases / Q000635:transmission / Q000821:virology; D011784:Quail / Q000821:virology*; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D014132:Trachea / Q000821:virology; D014779:Virus Replication
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus; C109963:hemagglutinin, avian influenza A virus