Figure captions
Figure 1 :Typical clinical signs and pathological changes were observed in PRV-infected goats, such as skin itch and fidgety (A&B ), diarrhea (C ). Also, severe hyperemia and hemorrhage were shown on the cerebrum from the infected goat (D ).
Figure 2 : Isolation and identification of YNG strain from goat. (A ) Obvious the cytopathic effects (CPE) of PK15 cells induced by the infection of the third passages of YNG strain, the CPE of cells in the left were characterized by being rounded and floated. The right cells were set as negative group, Scale bar = 200 um. (B ) The existence of infectious PRV virions in the cell cultures of the first, second, third, fifth, and seventh passages were confirmed via PCR, which could yielded the expected DNA bands (~450 bp) of PRV gE in 1% agarose gel electrophoresis. DNA+ and DNA– were regarded as positive and negative controls during DNA extraction, respectively. And PCR- was the negative control during PCR amplification. (C ) Indirect immunofluorescent assay (IFA) for the detection of PRV in Vero cells using anti-PRV gE and gB primary antibodies. Scale bar = 100 um
Figure 3 : The proliferation characteristics of YNG strains in vitro. (A ) One-step growth curves of YNG and YNP strains on PK15 and Vero cells at MOI of 0.01, the total PRV copies from the supernatant and cells in triplicates were measured via real-time PCR. (B ) The viral titers of YNG and YNP at 36 hpi were determined in PK15 cells by TCID50.
Figure 4: Analysis of sequence variation in YNG strain. (A ) A 7-aa insertion (64AASTPAA70) in the gC gene of PRV strains in genotype II compared with that in genotype I. (B ) A 2-aa deletion (278SP279) in the gD gene of PRV variants in genotype II and Becker strain compared with that of classical PRV strains in genotype II. (C ) A 3-nt deletion (1469ACG1471) encoding D at the position of 490 in the gE gene of YNG strain and another variant PRV strain prevalent in China (GenBank no. MK806387 (JX/CH/2016) compared with that of the other strains. (D&E ) Phylogenetic trees based on gC and gE gene sequences of YNG strain and other reference strains generated by the neighbor-joining method in MEGA 7.0 software. The red and black prismatic represented YNG strain obtained in this study and PRV strain isolated from human, respectively.
Figure 5 : The pathogenicity of YNG strain in mouse model. (A ) Survival curve (n=6/group) in Kunming mice after intramuscular injection with different PRV strains (104 TCID50/mouse). (B ) Pathological changes of cerebrum from mouse in different groups. (C ) The viral copies in different organs from mice infected with different PRV strains were determined according to the standard curve constructed by the threshold cycle (CQ) values of the serial 10-fold dilution of standard plasmid with known copies via real-time PCR method. Values are means±standard deviation (SD) = 3, significant differences were determined when P>0.05 (ns), P<0.05(*), P<0.01(**), and P<0.001(***).