3.3. Phylogenetic analysis
For precise phylogenetic classification, the relationship of PCV4 with 7
families of CRESS DNA viruses (Rosario et al., 2012; L. Zhao et al.,
2019) was inferred. The phylogenetic tree (inserted panel, Figure 7)
revealed a similar tree topology between 7 families as in the previous
publications (Kazlauskas et al., 2018; Krupovic et al., 2020). Based on
that result, four PCV4 sequences (including E115 strain) were clustered
within family Circoviridae . Using reference Rep sequences of
genera Circovirus and Cyclovirus of the familyCircoviridae , all PCV4 strains were seen belonging to genusCircovirus (Figure 7). In consistency with the early
classification (Tian et al., 2020; Zhang et al., 2020), this study
confirmed that PCV4 is distantly related to previously known PCV1, PCV2
and PCV3.