title: Vertebrate attenuated West Nile virus mutants have differing effects on vector competence in Culex tarsalis mosquitoes.
abstract: Previous mutational analyses of naturally occurring West Nile virus (WNV) strains and engineered mutant WNV strains have identified locations in the viral genome that can have profound phenotypic effect on viral infectivity, temperature sensitivity and neuroinvasiveness. We chose six mutant WNV strains to evaluate for vector competence in the natural WNV vector Culex tarsalis, two of which contain multiple ablations of glycosylation sites in the envelope and NS1 proteins; three of which contain mutations in the NS4B protein and an attenuated natural bird isolate (Bird 1153) harbouring an NS4B mutation. Despite vertebrate attenuation, all NS4B mutant viruses displayed enhanced vector competence by Cx. tarsalis. Non-glycosylated mutant viruses displayed decreased vector competence in Cx. tarsalis mosquitoes, particularly when all three NS1 glycosylation sites were abolished. These results indicate the importance of both the NS4B protein and NS1 glycosylation in the transmission of WNV by a significant mosquito vector.
authors.affiliation: The Arbovirus Laboratories, Wadsworth Center, New York State Dept. of Health, NY 12159, USA.
authors.forename: Greta A
authors.initials: GA
authors.lastname: Van Slyke
authors.affiliation: The Arbovirus Laboratories, Wadsworth Center, New York State Dept. of Health, NY 12159, USA.
authors.forename: Yongqing
authors.initials: Y
authors.lastname: Jia
authors.affiliation: Department of Pathology, Sealy Center for Vaccine Development, Center for Biodefense and Emerging Infectious Diseases, and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston TX 77555-0436, USA.
authors.forename: Melissa C
authors.initials: MC
authors.lastname: Whiteman
authors.affiliation: Department of Pathology, Sealy Center for Vaccine Development, Center for Biodefense and Emerging Infectious Diseases, and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston TX 77555-0436, USA.
authors.forename: Jason A
authors.initials: JA
authors.lastname: Wicker
authors.affiliation: Department of Pathology, Sealy Center for Vaccine Development, Center for Biodefense and Emerging Infectious Diseases, and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston TX 77555-0436, USA.
authors.forename: Alan D T
authors.initials: ADT
authors.lastname: Barrett
authors.affiliation: School of Public Health, State University of New York, NY 12205, USA.|The Arbovirus Laboratories, Wadsworth Center, New York State Dept. of Health, NY 12159, USA.
authors.forename: Laura D
authors.initials: LD
authors.lastname: Kramer
mesh_terms: D000818:Animals; D003465:Culex / Q000821:virology*; D005260:Female; D006031:Glycosylation; D007303:Insect Vectors / Q000821:virology*; D009154:Mutation; D013696:Temperature; D014481:United States; D014714:Vertebrates / Q000821:virology*; D017361:Viral Nonstructural Proteins / Q000235:genetics* / Q000378:metabolism; D014901:West Nile Fever / Q000635:transmission* / Q000821:virology; D014902:West Nile virus / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*
chemical_list: D017361:Viral Nonstructural Proteins