Hongxing Shen

Recombination analysis reveals a double recombination event in hepatitis E virus

Recombination of Hepatitis E Virus (HEV) has rarely been reported. In the present study, phylogenetic and recombination analyses were performed on 134 complete HEV genomes. Three potentially significant recombination events, including both intra-genotype and one inter-genotype, were identified by recombination detection analysis. Recombination events I and II occurred intra-genotype and inter-genotype, respectively, among three isolates, including the lineage represented by CHN-XJ-SW13 (GU119961, swine isolate), E067-SIJ05C (AB369690, human isolate), and JJT-Kan (AB091394, human isolate), and lead to the recombinant swine isolate swCH31 (DQ450072). Recombination event III occurred between the lineage represented by the NA1 (M73218) and K52-87 (L25595), which resulted in the recombinant Xingjiang-1 (D11092). Our analyses proved that that recombination could occur between human and swine HEV strains, double recombination events existed in HEV, and recombination event could happen within ORF2 region of HEV. These results will provide valuable hints for future research on HEV diversity.

Recombination analysis based on the complete genome of bocavirus

Bocavirus include bovine parvovirus, minute virus of canine, porcine bocavirus, gorilla bocavirus, and Human bocaviruses 1-4 (HBoVs). Although recent reports showed that recombination happened in bocavirus, no systematical study investigated the recombination of bocavirus. The present study performed the phylogenetic and recombination analysis of bocavirus over the complete genomes available in GenBank. Results confirmed that recombination existed among bocavirus, including the likely inter-genotype recombination between HBoV1 and HBoV4, and intra-genotype recombination among HBoV2 variants. Moreover, it is the first report revealing the recombination that occurred between minute viruses of canine.

BM61 of Bombyx mori nucleopolyhedrovirus: Its involvement in the egress of nucleocapsids from the nucleus

All lepidopteran baculovirus genomes sequenced encode a homolog of the Bombyx mori nucleopolyhedrovirus orf61 gene (Bm61). To determine the role of Bm61 in the baculoviral life cycle, we constructed a Bm61 knockout virus and characterized it in cells. We observed that the Bm61 deletion bacmid led to a defect in production of infectious budded virus (BV). Quantitative PCR analysis of BV in the media culturing the transfected cell indicated that BV was not produced due to Bm61 deletion. Electron microscope analysis showed that in the knockout of Bm61, nucleocapsids were not transported from the nucleus to the cytoplasm. From these results we concluded that BM61 is required in the BV pathway for the egress of nucleocapsids from the nucleus to the cytoplasm.

Characterization of the Bm61 of the Bombyx mori Nucleopolyhedrovirus

Abstractorf61 (bm61) of Bombyx mori Nucleopolyhedrovirus (BmNPV) is a highly conserved baculovirus gene, suggesting that it performs an important role in the virus life cycle whose function is unknown. In this study, we describe the characterization of bm61. Quantitative polymerase chain reaction (qPCR) and western blot analysis demonstrated that bm61 was expressed as a late gene. Immunofluorescence analysis by confocal microscopy showed that BM61 protein was localized on nuclear membrane and in intranuclear ring zone of infected cells. Structure localization of the BM61 in BV and ODV by western analysis demonstrated that BM61 was the protein of both BV and ODV. In addition, our data indicated that BM61 was a late structure protein localized in nucleus.

Identification of recombination between Muscovy duck parvovirus and goose parvovirus structural protein genes

Waterfowl parvoviruses are divided into Muscovy duck parvoviruses (MDPVs) and goose parvoviruses (GPVs). Phylogenetic analysis based on structural gene nucleotide sequences showed that the strains of three GPVs (DY, PT and D strains) and two MDPVs (GX5 and SAAH-SHNH) are closely related and formed one cluster. Recombination analysis showed that recombination between GPV-GDFsh and MDPV-89384/FRANCE strains led to five recombinant strains: GPV-DY, GPV-PT, GPV-D, MDPV-GX5 and MDPV-SAAH-SHNH. The recombinant event was confirmed using the Simplot program and phylogenetic analysis. This is the first comprehensive investigation of recombination between MDPV and GPV structural genes.

Identification of recombination in the NS1 and VPs genes of parvovirus B19

Human parvovirus B19 (B19V), a member of the genus Erythrovirus of the family Parvoviridae, is a pathogenic virus distributed worldwide in the human population. In this study, we performed phylogenetic and recombination analysis of B19V based on the available nonstructural gene (NS1) and capsid proteins (VPs) genes in GenBank. Results indicated that recombination occurred between genotypes 3 and 1, leading to the recombinant cluster genotype 2. Other three inter‐genotype recombination events were also discovered. Moreover, our results showed that among the four recombinant events in the present study, all of the major parents belonged to genotype 1, the minor parents were from genotypes 3 or 2, and all of the recombinants belonged to genotype 2. These recombinant events were confirmed by SimPlot Program and phylogenetic analysis. J. Med. Virol. 88:1457–1461, 2016.

Characterization of a Late Expression Gene of Bombyx mori Nucleopolyhedrovirus

Bombyx mori nucleopolyhedrovirus (BmNPV) ORF5 (Bm5) is a gene present in many lepidopteran nucleopolyhedroviruses (NPVs), but its function is unknown. In this study, Bm5 was characterized. The transcript of Bm5 was detected 12 - 72 h post infection (p.i.). Polyclonal antiserum raised to a His-BM5 fusion protein recognized BM5 in infected cell lysates from 24 to 72 h p.i., suggesting that Bm5 is a late gene. Immunofluorescence analysis by confocal microscopy showed that the BM5 protein is localized primarily in the cytoplasm. Localization of BM5 in budded virion (BV) and occlusion-derived virion (ODV) by Western analyses demonstrated that BM5 is not a structural protein associated with BV or ODV.

Characterization of Bombyx mori nucleopolyhedrovirus with a knockout of Bm17

Open reading frame 17 (Bm17) gene of Bombyx mori nucleopolyhedrovirus is a highly conserved gene in lepidopteran nucleopolyhedroviruses, but its function remains unknown. In this report, transient-expression and superinfection assays indicated that BM17 localized in the nucleus and cytoplasm of infected BmN cells. To determine the role of Bm17 in baculovirus life cycle, we constructed a Bm17 knockout virus and characterized its properties in cells. Analysis of the production and infection of budded virions, the level of viral DNA replication revealed showed that there was no significant difference among the mutant, the control, and the Bm17 repaired virus strains. These results suggest that BM17 is not essential for virus replication in cultured cells.

Echovirus plays major roles in the natural recombination of Coxsackievirus B3

Coxsakievirus B3 (CVB3) is a member of enterovirus B (EVB) group, which can cause serious heart diseases such as viral myocarditis. In order to analyze the evolution of CVB3, we performed a recombination analysis of all viral genomes of enterovirus B, and found that there were 19 putative recombination events that produced CVB3. A total of 11 serotypes were found to be involved in the generation of CVB3 progeny virus. These recombination events involved echovirus, EcoV (which includes EcoV6, EcoV9, EcoV14, EcoV15, EcoV17, EcoV21, EcoV24, and EcoV25), CVB4, CVB5, and EVB81, as major or minor parents. The most active, EcoV, which was involved in the 14 of 19 recombination events, acts as one of the parental viruses for CVB3 strains among molecular evolution and recombination events in circulating CVB3. Our study indicates that, EcoV plays major roles in CVB3 recombination, and is involved in the production of 11 new CVB3 recombinant strains.

Recombination analysis of coxsackievirus B5 genogroup C

Coxsackievirus B5 (CVB5) is a member of the species Enterovirus B of the genus Enterovirus, family Picornaviridae. Based on its VP1 sequence, CVB5 is divided into four genogroups: A, B, C, and D. From 2002 to 2012, CVB5 serotype genogroup C caused an outbreak of aseptic meningitis in China. In order to study the evolution of CVB5 genogroup C, phylogenetic and recombination analysis was performed using the 399 available enterovirus B genome sequences in the GenBank database. The results indicated that 10 strains of CVB5 serotype genogroup C resulted from recombination between members of genogroup B and echovirus serotype E6, and another 5 strains resulted from recombination between members of genogroup C and serotype CVB4. These recombination events were confirmed by phylogenetic analysis.