Figure 3.

The time-ordered genetic divergence pattern of the RdRp- and VP1-encoding nucleotide sequences of major sapovirus genotypes. Root-to-Tip linear regression analyses were performed to investigate the association between genetic divergence of the (a) RdRp- and (b) VP1-encoding nucleotide sequences and collection years. The x-axis indicates the collection year and the y-axis shows the root-to-tip divergence on the maximum-likelihood tree. Linear lines indicate the best-fit linear regression of root-to-tip divergence, based on the collection years. Strains are represented by grey dots.