Influenza A viral segments NP, M, and NS conservation plots in human, avian, and swine strains. For intra-host comparisons, the PB1 segment is the most conserved in human strains. This is followed by PB2, NP, PA, NS, and finally M. In avian strains, NS is most conserved, followed by M, PB1, NP, PA, and finally PB2. In swine strains, M is most conserved followed by NP, PB2, PA, and finally PB1.
ElHefnawi et al. Virology Journal 2011 8:44 doi:10.1186/1743-422X-8-44