@article{9006e4c03c194070997fbcbc7448cc0c,
title = "Limited evolution of West Nile virus has occurred during its southwesterly spread in the United States",
abstract = "Analysis of partial nucleotide sequences of nine West Nile virus strains isolated in southeast Texas during June-August 2002 revealed a maximum of 0.35% nucleotide variation from a New York 1999 strain. Two sequence subtypes were identified that differed from each other by approximately 0.5%, suggesting multiple introductions of virus to this area. Analysis of sequences from cloned PCR products for one strain revealed up to 0.6% divergence from the consensus sequence at the subpopulation level. The presence of unique patterns of small numbers of mutations in North American West Nile strains studied to date may suggest the absence of a strong selective pressure to drive the emergence of dominant variants.",
author = "Beasley, {David W C} and Davis, {C. Todd} and Hilda Guzman and Vanlandingham, {Dana L.} and {Travassos Da Rosa}, {Amelia P A} and Parsons, {Ray E.} and Stephen Higgs and Tesh, {Robert B.} and Barrett, {Alan D T}",
note = "Funding Information: The authors thank Darci Smith for assistance with some studies; Steve Smith, Esther Surriga, and Steve Burkett from the UTMB Biomolecular Resource Facility DNA sequencing laboratory for sequencing support; and Tom Solomon and Mike Holbrook for critical reading of the manuscript. This study was supported in part by NIH Grant AI- 10984, CDC Cooperative Agreements U90/CCU620916-01 and U50/CCU620539-01, and funding from the State of Texas Advanced Research Program.",
year = "2003",
month = may,
day = "10",
doi = "10.1016/S0042-6822(03)00150-8",
language = "English (US)",
volume = "309",
pages = "190--195",
journal = "Virology",
issn = "0042-6822",
publisher = "Academic Press Inc.",
number = "2",
}