An infectious clone of the West Nile flavivirus

Virology. 2001 Mar 15;281(2):294-304. doi: 10.1006/viro.2000.0795.


West Nile (WN) virus is the most widespread among flaviviruses, but until recently it was not known on the American continent. We describe here design of a subgenomic replicon, as well as a full-length infectious clone of the lineage II WN strain, which appeared surprisingly stable compared to other flavivirus infectious clones. This infectious clone was used to investigate effects of 5'- and 3'-nonrelated sequences on virus replication and infectivity of synthetic RNA. While a long nonrelated sequence at the 3'-end delayed but did not prevent establishment of the productive infectious cycle, a much shorter extra sequence at the 5'-end completely abrogated virus replication. Replacement of the conserved 5'-adenosine residue substantially delayed, but did not prevent, establishment of virus infection. In all cases, the recovered virus had restored its authentic 5'- and 3'-end genome sequences. However, the presence of extensive nonrelated sequences at both 5'- and 3'-ends could not be repaired.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3' Untranslated Regions / genetics
  • 5' Untranslated Regions / genetics
  • Cell Line
  • Cloning, Molecular
  • Escherichia coli / genetics
  • Genome, Viral*
  • Replicon
  • Transcription, Genetic
  • Transfection
  • Virus Replication / genetics
  • West Nile virus / genetics*
  • West Nile virus / pathogenicity


  • 3' Untranslated Regions
  • 5' Untranslated Regions