Fig. 29From: Diversity and distribution of type A influenza viruses: an updated panorama analysis based on protein sequencesPhylogenetic diversity and distribution of IAVs based on PA gene sequences. Based on the viral PA gene sequences, IAVs were classified into four primary lineages, PA.1, PA.2, PA.3, and PA.4 which mainly corresponded to AIVs, HuIVs, SIVs, and EIVsBack to article page