Fig. 3.

Phylogenetic relationships of the NA gene of A/swine/Guangdong/L3/2009 and A/swine/Guangdong/L6/2009 compared to genetically related influenza viruses. Horizontal distances are proportional to the minimum number of nucleotide differences required to join nodes and sequences. Vertical distances are for spacing branches and labels. The phylogenetic trees were generated by using the neighbor-joining algorithm. The percentage of replicate trees in which the associated taxa clustered together in the bootstrap test (1,000 replicates) is shown next to the branches