Appendix Figure. Phylogenetic analysis of avian influenza viruses (H5N1). A) hemagglutinin genes and B) polymerase A genes. Pseudosampling = 1,000. Known genotype V viruses are indicated in red, and genotype Z viruses are indicated in blue. Numbers on the right in braces indicate clades and subclades. Scale bars indicate genetic distances between sequences of different taxa. HK, Hong Kong.