title: Evolutionary genetics and vector adaptation of recombinant viruses of the western equine encephalitis antigenic complex provides new insights into alphavirus diversity and host switching.
abstract: Western equine encephalitis virus (WEEV), Highlands J virus (HJV), and Fort Morgan virus (FMV) are the sole representatives of the WEE antigenic complex of the genus Alphavirus, family Togaviridae, that are endemic to North America. All three viruses have their ancestry in a recombination event involving eastern equine encephalitis virus (EEEV) and a Sindbis (SIN)-like virus that gave rise to a chimeric alphavirus that subsequently diversified into the present-day WEEV, HJV, and FMV. Here, we present a comparative analysis of the genetic, ecological, and evolutionary relationships among these recombinant-origin viruses, including the description of a nsP4 polymerase mutation in FMV that allows it to circumvent the host range barrier to Asian tiger mosquito cells, a vector species that is normally refractory to infection. Notably, we also provide evidence that the recombination event that gave rise to these three WEEV antigenic complex viruses may have occurred in North America.
authors.affiliation: Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA; Southeastern Cooperative Wildlife Disease Study, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA. Electronic address: aba75@cornell.edu.
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Allison
authors.affiliation: Southeastern Cooperative Wildlife Disease Study, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA; Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA.
authors.forename: David E
authors.initials: DE
authors.lastname: Stallknecht
authors.affiliation: Marie Bashir Institute for Infectious Diseases and Biosecurity, Charles Perkins Centre, School of Biological Sciences and Sydney Medical School, University of Sydney, New South Wales 2006, Australia.
authors.forename: Edward C
authors.initials: EC
authors.lastname: Holmes
mesh_terms: D000524:Alphavirus / Q000235:genetics* / Q000276:immunology*; D000595:Amino Acid Sequence; D000818:Animals; D000956:Antigens, Viral / Q000235:genetics*; D001483:Base Sequence; D009033:Culicidae / Q000821:virology; D004667:Encephalitis Virus, Western Equine / Q000235:genetics* / Q000276:immunology* / Q000472:pathogenicity; D020241:Encephalomyelitis, Western Equine / Q000635:transmission / Q000662:veterinary* / Q000821:virology; D019143:Evolution, Molecular; D014644:Genetic Variation; D006734:Horse Diseases / Q000635:transmission / Q000821:virology*; D006736:Horses; D058507:Host Specificity; D007303:Insect Vectors / Q000821:virology; D008969:Molecular Sequence Data; D009154:Mutation; D009656:North America; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics; D011995:Recombination, Genetic
chemical_list: D000956:Antigens, Viral; D012367:RNA, Viral
keywords: Alphavirus; Fort Morgan virus; Highlands J virus; Host range; Recombination; Togavirus; Virus emergence; Western equine encephalitis antigenic complex; Western equine encephalitis virus