Figure 4From: Synergistic effect of PB2 283M and 526R contributes to enhanced virulence of H5N8 influenza viruses in mice Polymerase activities of reconstituted RNP complex and correlation of virulence of recombinant virus with polymerase activity. Comparison of polymerase activities of different ribonucleoprotein complexes with A indicated a single polymerase gene or NP from the CZ or JY virus, and with B indicated two or three polymerase genes from the CZ or JY virus, and with C indicated single or double substitution in the PB2 of the CZ or JY virus. Values represent the mean ± SD of the results of three independent experiments and are standardized to those of the JY (100%). The relative polymerase activity value of each recombinant virus was compared with that of the corresponding parental virus (*P < 0.05; **P < 0.01). D Correlation of virulence of recombinant virus with polymerase activity. The MLD50 of viruses were plotted (inverted axis) against their polymerase activities.Back to article page