Fig. 2.

Phylogenetic trees of H6 HA and N2 and N8 NA genes. Trees were generated by the neighbor-joining method with the PAUP* program. Numbers above branches indicate neighbor-joining bootstrap values. Not all supports are shown because of space constraints. Analysis was based on nucleotides 22 to 1036 (HA), 249 to 1303 (N2), and 41 to 1341 (N8). The H6 tree was rooted to A/mallard/Potsdam/178-4/83 (H2N2). The N2 tree was rooted to A/equine/Prague/1/1956 (H7N7). The N8 tree was rooted to A/ruddy turnstone/Delaware/97/2000 (H12N5). Viruses characterized in this study are highlighted in red. Scale bar, 0.1 substitutions per site.