SUPPLEMENTARY FIGURE A14-3 Phylogenetic relationships of each gene segment (PB2, PB1, PA, HA, NP, NA, M & NS) of swine influenza A viruses indicating genetic components of the swine-origin influenza A (H1N1) virus. Clade labels indicate major swine lineages. Human viruses are coloured blue, swine viruses in red and avian viruses in green.