Figure 3

Nucleotide (upper bars) and amino acid (lower bars) substitutions into the genome of China cVDPV isolates.
Sabin 1 was used as the reference sequence. The substitution maps are aligned with a schematic of the poliovirus genome. The single open reading frame (ORF), flanked by 5′-UTR and 3′-UTR, is indicated by a rectangle; the internal ribosome entry site (IRES) in the 5′-UTR is indicated by a shaded rectangle. The triangles indicate back mutations to the Mahoney strain, among them, red triangles indicate back mutations related to the general accepted neurovirulence sites and blue triangles indicate back mutations have nothing to do with the general accepted neurovirulence sites; the dashed arrows indicate the absence of back mutation of the major determinant in the IRES (nt480).