FIGURE LEGENDS
Table 1Recombinant
outcome detected using the Recombination Detection Program v4.56.
Table 2Detection
of viral loads in tissues and body fluids of rabbits infected with RHDV2
(SC20-01 strain).
Fig. 1Details
of the first case of RHD caused by RHDV2 in China.(A)
The location of the first case of RHD caused by RHDV2 in China. (B)
Clinical signs of infected rabbits. Dead rabbits show typical clinical
signs of RHD, including anorexia, cachexia, opisthotonos, and bloody
nasal discharge. (C) Pathological tissue changes in infected rabbits.
The major pathological changes of tissues are haemorrhages and
congestions in the lungs, as well as acute hepatitis.
Fig. 2TEM
images of viral particles extracted from supernatants of homogenized
livers of the infected rabbits. Supernatants of homogenized livers were
clarified with 30% sucrose solution. Icosahedral symmetry viral
particles were observed with a diameter ranging from 30 to 40 nm, which
was consistent with those of RHDV.
Fig. 3Phylogenetic
analysis of RHDV2 China isolation strain SC20-01. (A) Maximum
likelihood tree for RHDV based on the VP60 protein using MEGA5.0
software. RHDV isolation strain SC20-01 belonged to the RHDV2 subtype
and was most closely related with several isolation strains in Europe.
(B) Nucleotide sequence divergence scans and Bootscanning of RHDV.
Recombination events of the SC20-01 strain were examined using SimPlot
with one apparent breakpoint that separated the SC20-01 genome into two
regions being detected.
Maximum likelihood tree for RHDV based on the non-structural
(10~5304 bp) (C) and structural protein-coding regions
(5304~7378bp) (D) using MEGA5.0 software. The
non-structural protein-coding region of SC20-01 was more closely related
with that of classic RHDV than RHDV2. Further, the results indicated
that SC20-01 was a classic RHDV/RHDV2 recombination strain.
Fig. 4Animal
regress experiment of SPF rabbits infected with RHDV2 China isolation
strain SC20-01. (A) SPF rabbits infected with SC20-01 strain showed
typical clinical signs and pathological changes of RHD. SC20-01 strain
was highly fatal and could cause the death of the SPF rabbits after 24
post-injection hours. (B) IHC analysis of tissues from rabbits in both
groups. Images of IHC analysis showed that VP60 of RHDV2 was present in
the tissues of the rabbits in the experiment group and was mainly
located in the cellular cytoplasm.