Figure 2.

A phylogenetic tree based on the complete nucleotide sequences of the WNV lineage 2 polyprotein (10,302 nt) using the maximum likelihood method and Tamura–Nei model. A discrete gamma distribution was used to model the evolutionary rate differences among sites (5 categories (+ G, parameter = 0.2474)). The tree is drawn to scale, with branch lengths measured according to the number of substitutions per site. The percentage of trees in which the associated taxa are clustered together is shown next to the branches; only values >80% are shown. The tree is drawn to scale. The sequences of the present study are marked with a circle; the first Greek sequence (HQ537483) is marked with a triangle. The names of countries are shown in capital letters; all other sequences are from Greece.