Figure legends
FIGURE 1 Brain lesions in the cub. Young lion mainly developed brain tissue changes, such as hydrocephalus, a 5cm cavity in the center of the brain
FIGURE 2 FPV-related diseased tissue, lion (original magnification x400) (A) The brain showed typical encephalitis with glial cell proliferation, neuronal atrophy and necrosis, and encephalomalacia. (B) The cerebellum showed nerve cell necrosis and capillary congestion. (C) The spinal cord showed vesicular degeneration. (D) Limb nerves showed partial necrosis
FIGURE 3 Virus isolation and cytopathic effects of the FPV HN-ZZ2 strain in CRFK cells (original magnification x200). The FPV-positive samples were treated and inoculated into CRFK cells. The cytopathogenic effects induced by the FPV HN-ZZ2 strain observed in CRFK cells 24, 48, 60hours after inoculation were observed by light microsopy
FIGURE 4 Identification in infected cells of FPV HN-ZZ2 through IFA. (A) Cells infected with FPV are shown. Green fluorescence represents the FPV antigen within infected cells. (B) Negative control
FIGURE 5 Transmission electron microscopy technique of FPV HN-ZZ2. The diameter of the virion was approximately 20-25 nm which was observed under the electron microscope and revealed no envelope, spherical shape, and the icosahedral structure, and these were consistent with the structural characteristics of Feline FPV
FIGURE 6 The phylogenetic tree constructed from the full sequences of the HNZZ2 strain and the reference sequences. The branch lengths are drawn to scale (number of substitutions per site). The trees were rgenerated by the neighbor-joining method with bootstrap tests of 1000 replicates using the MEGA 7 software. The bootstrap support is indicated above the respective branches with an asterisk. The FPV HN-ZZ2 strain described in the current study is indicated. The GenBank accession numbers of the sequences under study are provided in Table 2
FIGURE 7 The results of a recombination breakpoint analysis performed using the RDP4 and Simplot program. (A and B) Recombination detection by the RDP4 program shows that FPV HN-ZZ2 is generated from recombination between CPV-L/Cania/China and canine Raccoon/RC9/BC2010/Procyon lotor/Canada. Nucleotide position 2,841 is identified as an ending breakpoint. A predicted recombination region is found around positions 1,956 and 2,841 of the alignment. (C) The Simplot program identifies nucleotide position 2,580 as a putative breakpoint for recombination
FIGURE 8Phylogenetic trees were inferred for the nucleotides of the NS1(A) and VP2(B)genes. The trees were generated by the neighbor-joining method with bootstrap tests of 1000 replicates using the MEGA 7 software. The FPV HN-ZZ2 strain isolated in the current study is indicated
TABLE 1 Primers used for amplification and sequencing of FPV HN-ZZ2