1. A positively selected mutation in the WNV 2K peptide confers resistance to superinfection exclusion in vivo.
- Author
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Campbell CL, Smith DR, Sanchez-Vargas I, Zhang B, Shi PY, and Ebel GD
- Subjects
- Animals, Humans, Viral Nonstructural Proteins chemistry, Viral Nonstructural Proteins metabolism, Virus Replication, West Nile virus chemistry, West Nile virus physiology, Culex virology, Insect Vectors virology, Mutation, Missense, Superinfection virology, Viral Nonstructural Proteins genetics, West Nile Fever virology, West Nile virus genetics
- Abstract
Molecular epidemiologic studies of North American (NA) West Nile virus (WNV; Flaviviridae, Flavivirus) have documented the displacement of the introduced NY99 genotype with WN02. In addition, these studies have shown that particular substitutions are under positive selection. One occurs in the C-terminus of the NS4A coding sequence and results in a valine to methionine substitution at position nine of the 2K peptide. 2K-V9M confers the ability to overcome superinfection exclusion in vitro. We hypothesized that WNV strains bearing 2K-V9M have higher fitness than wildtype in Culex quinquefasciatus mosquitoes. Although infection rates and viral titers were not significantly different, virus dissemination rates were significantly higher with WNV 2K-V9M. As a super-infecting virus, WNV 2K-V9M was more successful than wildtype, however, in a mixed infection, 2K-V9M was not. These data support observations that 2K-V9M confers a context-specific selective advantage in mosquitoes and provides an in vivo mechanism for its positive selection., (Copyright © 2014 Elsevier Inc. All rights reserved.)
- Published
- 2014
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