Bulk-SSR method was used to analyze the genetic diversity of 44 open-pollinated varieties collected from Henan, Shandong, Shanxi, and Jilin provinces and Guangxi Zhuang Autonomous Region, China using 70 pairs of SSR p...Bulk-SSR method was used to analyze the genetic diversity of 44 open-pollinated varieties collected from Henan, Shandong, Shanxi, and Jilin provinces and Guangxi Zhuang Autonomous Region, China using 70 pairs of SSR primers. The purposes of this study were to （1） compare the genetic diversity among 44 Chinese maize open-pollinated varieties; （2） estimate the minimum number of alleles for construction of a stable dendrogram; and （3） trace the genetic relationships among local germplasm from different regions of China. In total, these 70 SSR primers yielded 292 alleles in 176 samples （4×44） analyzed. The number of alleles per locus was 4.17 on average and ranged from 2 to 8. The highest number of alleles per open-pollinated variety （55.25） was detected in Shanxi germplasm, which indicated that open-pollinated varieties from Shanxi possessed the largest genetic diversity among those from the five locations. The correlation coefficients between different genetic similarity matrices suggested that 200 alleles were sufficient for analysis of the genetic diversity of these 44 open-pollinated varieties. The cluster analysis showed that 44 open-pollinated varieties collected from three growing regions in China were accurately classified into three groups that were highly consistent with their geographic origins, and there is no correlation between GS and geographic distance in this study.展开更多
Q Sepharose Fast Flow(Q Sepharose F.F.) was adopted to purify the suspensions of type Ⅰ,Ⅱ,Ⅲ oral poliovaccine (OPV), which is prepared from Vero cells. After clarification and concentration by ultrafiltration,th...Q Sepharose Fast Flow(Q Sepharose F.F.) was adopted to purify the suspensions of type Ⅰ,Ⅱ,Ⅲ oral poliovaccine (OPV), which is prepared from Vero cells. After clarification and concentration by ultrafiltration,the recovery of virus infected titre may attain above 85%.Using column chromatography on Q Sepharose F.F. to purify the concentrated virus suspensions,the purified viruses attain 100% recovery of virus infectivity. Dot membrane hybrization was used to detect DNA with the probe of Vero cell genome DNA which was labeled with α P 32 dATP,the contents of residual substrate DNA was less than 100 Pg/dose. The process of downstream had no significant influence on some biological characters of purified viruses,such as virus morphology ,tumorigenicity, rct/40 character and capsid protein.This downstream reseach indicates that Q Sepharose F.F. is an ideal chromatography material for purifying OPV prepared from Vero cells.展开更多
Results of triplet-triplet energy transfer from biacetyl to OPVs and OPV tripiet state quenching by 1, 4-diazabicyclo[2.2.2] octane (DABCO) suggested that tripiet state of oligophenylenevinylenes(OPVs) directly takes ...Results of triplet-triplet energy transfer from biacetyl to OPVs and OPV tripiet state quenching by 1, 4-diazabicyclo[2.2.2] octane (DABCO) suggested that tripiet state of oligophenylenevinylenes(OPVs) directly takes part in their photooxidative degradation instead of just generating singlet oxygen.展开更多
Ectromelia virus(ECTV),a member of the Orthopoxvirus genus,serves as both a causative agent of mousepox and a pivotal surrogate model for studying highly pathogenic orthopoxviruses.Although genomic data on ECTV remain...Ectromelia virus(ECTV),a member of the Orthopoxvirus genus,serves as both a causative agent of mousepox and a pivotal surrogate model for studying highly pathogenic orthopoxviruses.Although genomic data on ECTV remains limited,we report the isolation and characterization of a novel strain,ECTV-C-Tan-GD01,obtained from rodents in Guangdong Province,China.Nanopore sequencing yielded a complete genome(199 annotated genes,including one gene truncated at the C-terminus)with inverted terminal repeats(ITRs)harboring a conserved hairpin structure.Notably,a frameshift-inducing“G”deletion in the EV159 gene resulted in the truncation of a semaphorin-like protein.In vitro assays demonstrated cell-associated viral replication kinetics,with maximum titers achieved earlier in Vero/HeLa cells(72 h)than in BHK-21/CEF cells(84 h).Murine challenge experiments revealed extreme virulence(LD50<1 plaque-forming unit(PFU)via intranasal/footpad routes)and hepatosplenic tropism.Furthermore,ECTV-C-Tan-GD01 exhibited utility in evaluating orthopoxvirus countermeasures:a single dose of vaccinia virus Tiantan(VTT)or non-replicating vaccinia virus Tiantan(NTV)conferred cross-protection,while tecovirimat(ST-246),cidofovir(CDV),and brincidofovir(initially CMX001)significantly reduced viral loads and pathology.This study establishes ECTV-C-Tan-GD01 as a dual-purpose resource for probing orthopoxvirus evolution and advancing therapeutic development.展开更多
基金supported by the National Natural Science Foundation of China (30571169)the Earmarked Fund for Modern Agro-Industry Technology Research System of Maize, Ministry of Agriculture, China (2006-G3)
文摘Bulk-SSR method was used to analyze the genetic diversity of 44 open-pollinated varieties collected from Henan, Shandong, Shanxi, and Jilin provinces and Guangxi Zhuang Autonomous Region, China using 70 pairs of SSR primers. The purposes of this study were to （1） compare the genetic diversity among 44 Chinese maize open-pollinated varieties; （2） estimate the minimum number of alleles for construction of a stable dendrogram; and （3） trace the genetic relationships among local germplasm from different regions of China. In total, these 70 SSR primers yielded 292 alleles in 176 samples （4×44） analyzed. The number of alleles per locus was 4.17 on average and ranged from 2 to 8. The highest number of alleles per open-pollinated variety （55.25） was detected in Shanxi germplasm, which indicated that open-pollinated varieties from Shanxi possessed the largest genetic diversity among those from the five locations. The correlation coefficients between different genetic similarity matrices suggested that 200 alleles were sufficient for analysis of the genetic diversity of these 44 open-pollinated varieties. The cluster analysis showed that 44 open-pollinated varieties collected from three growing regions in China were accurately classified into three groups that were highly consistent with their geographic origins, and there is no correlation between GS and geographic distance in this study.
文摘Q Sepharose Fast Flow(Q Sepharose F.F.) was adopted to purify the suspensions of type Ⅰ,Ⅱ,Ⅲ oral poliovaccine (OPV), which is prepared from Vero cells. After clarification and concentration by ultrafiltration,the recovery of virus infected titre may attain above 85%.Using column chromatography on Q Sepharose F.F. to purify the concentrated virus suspensions,the purified viruses attain 100% recovery of virus infectivity. Dot membrane hybrization was used to detect DNA with the probe of Vero cell genome DNA which was labeled with α P 32 dATP,the contents of residual substrate DNA was less than 100 Pg/dose. The process of downstream had no significant influence on some biological characters of purified viruses,such as virus morphology ,tumorigenicity, rct/40 character and capsid protein.This downstream reseach indicates that Q Sepharose F.F. is an ideal chromatography material for purifying OPV prepared from Vero cells.
文摘Results of triplet-triplet energy transfer from biacetyl to OPVs and OPV tripiet state quenching by 1, 4-diazabicyclo[2.2.2] octane (DABCO) suggested that tripiet state of oligophenylenevinylenes(OPVs) directly takes part in their photooxidative degradation instead of just generating singlet oxygen.
基金supported by the Natural Science Foundation of Beijing(7254390)the Youth Science Foundation of Chinese Center for Disease Control and Prevention(2024A103)to W.C.C,the National Key ResearchDevelopment Program of China(2022YFC2304100,2023YFD1800405).
文摘Ectromelia virus(ECTV),a member of the Orthopoxvirus genus,serves as both a causative agent of mousepox and a pivotal surrogate model for studying highly pathogenic orthopoxviruses.Although genomic data on ECTV remains limited,we report the isolation and characterization of a novel strain,ECTV-C-Tan-GD01,obtained from rodents in Guangdong Province,China.Nanopore sequencing yielded a complete genome(199 annotated genes,including one gene truncated at the C-terminus)with inverted terminal repeats(ITRs)harboring a conserved hairpin structure.Notably,a frameshift-inducing“G”deletion in the EV159 gene resulted in the truncation of a semaphorin-like protein.In vitro assays demonstrated cell-associated viral replication kinetics,with maximum titers achieved earlier in Vero/HeLa cells(72 h)than in BHK-21/CEF cells(84 h).Murine challenge experiments revealed extreme virulence(LD50<1 plaque-forming unit(PFU)via intranasal/footpad routes)and hepatosplenic tropism.Furthermore,ECTV-C-Tan-GD01 exhibited utility in evaluating orthopoxvirus countermeasures:a single dose of vaccinia virus Tiantan(VTT)or non-replicating vaccinia virus Tiantan(NTV)conferred cross-protection,while tecovirimat(ST-246),cidofovir(CDV),and brincidofovir(initially CMX001)significantly reduced viral loads and pathology.This study establishes ECTV-C-Tan-GD01 as a dual-purpose resource for probing orthopoxvirus evolution and advancing therapeutic development.
