Figure 2

Phylogenetic analysis of HA and NA genes of H3N3 virus. A A simplified schematic showing the putative genomic composition of the H3N3 virus. The bars represent eight gene segments of AIVs (from top to bottom: PB2, PB1, PA, HA, NP, NA, M, and NS), and the bar’s colour indicates the gene segment’s closest donor strain. Phylogenetic trees were constructed using MEGA software (Version 11) with the Neighbor-Joining method. A bootstrap value of 1000 was used to estimate the statistical reliability of clades, and values higher than 90 were shown above the branch. The tree of B HA and C NA were rooted to A/equine/Uruguay/1/1963(H3N8) and A/tern/South Africa/1959 (H5N3), respectively. The H3N3 virus isolated in this study is shown in red, and viruses shown in blue are human isolates. The regions of nucleotide sequence used for the phylogenetic analyses were HA, 29–1732 and NA, 19–1431.