[Molecular evolution of the West Nile virus].

Molekuliarnaia genetika, mikrobiologiia i virusologiia

PubMedID: 24757840

Sixty eight nucleotide sequences encoding protein E of the West Nile virus (WNV) were used for the phylogenetic analysis and estimation of the evolution rate of the WNV. Nucleotide substitution accumulation rate was evaluated as 2.5 x 10(-4) substitutions per site per year. Phylogenetic analysis and divergence time estimation carried out using the molecular clocks methodology showed that genotypes 1, 2, and 4 of the WNV circulated in the area of the European Russia with estimated divergence times from a common ancestor of approximately 2360, 2800, and 5950 years ago, respectively. The non-synonymous (dN) to the synonymous (dS) substitution values were found between 0.022-0.275 for the different WNV strains that were grouped by geographical and/or filogenetic characteristics. The highest dN/dS values were found in the group of WNV isolates coming from Russia and North America that have disseminated in these new regions over the past 14 years. Estimation of dN/dS for WNV shows that the dN/ dS value can be used as an indicator of the intraspecies variability and for evaluation of evolution rate for new isolates of WNV. This confirms the hypothesis about of the favorable conditions for the wide dissemination and rapid evolution of different' genotypes of WNV occurring from 2 up to 6 thousand years ago in modern geographical and climatic conditions.