Genetic diversity and purifying selection in West Nile virus populations are maintained during host switching

Greta V S Jerzak, Ivy Brown, Pei-Yong Shi, Laura D. Kramer, Gregory D. Ebel

Research output: Contribution to journalArticle

52 Scopus citations


To investigate differential evolutionary rates and selective forces of WNV in hosts and vectors, we measured the genetic diversity that arose during alternating passage in mosquitoes and birds. Within-host genetic diversity was monitored in each of three experimentally passed replicates, and the complete genome sequence of each WNV strain was determined after passage. The intrahost genetic diversity that arose during alternating passage was significantly greater than the diversity generated during chicken-only passage and similar to mosquito-only passage. dN/dS ratios suggested purifying selection similar to chick-passed virus, but not to mosquito-passed virus. Thus, the abundant genetic variation contributed to WNV populations through infection of mosquitoes and the strong purifying selection contributed by infection of birds may be maintained despite frequent host switching.

Original languageEnglish (US)
Pages (from-to)256-260
Number of pages5
Issue number2
StatePublished - May 10 2008
Externally publishedYes



  • Arbovirus
  • Flavivirus
  • Host switching
  • Natural selection
  • Quasispecies
  • West Nile virus

ASJC Scopus subject areas

  • Virology
  • Infectious Diseases

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