3.Analysis of genetic characteristics of wild-type measles viruses in Jilin Province 2005.
Jiang BIAN ; Fan LI ; Shi-hong YI
Chinese Journal of Preventive Medicine 2006;40(5):348-350
OBJECTIVETo investigate the know gene types of main wild type measles virus strains and take measures to control measles in Jilin Province.
METHODSGenetic characterization of 9 measles viruses isolated from 72 throat swabs or urine specimens of measles patients using CDW(150) cells line was studied in Jilin Province in 2005.
RESULTSSequence analysis of 450 nucleotides of COOH-terminal of nucleoprotein (N) genes of 9 isolates indicated that all were members of H(1) genotype, in which there are 7 strains of H1a and 2 strains of H1b, the H1a subgroup differed from H1b by 2.0% approximately 3.5% at the nucleotide level in the COOH-terminal of the N gene.
CONCLUSIONSThe H(1) genotype of wild-type measles viruses should be the main epidemic strain and main pathogen that caused measles outbreaks and sporadic cases in Jilin Province.
China ; Genes, Reporter ; Genes, Viral ; Genotype ; Humans ; Measles ; epidemiology ; virology ; Measles virus ; genetics ; Molecular Sequence Data ; Viral Structural Proteins ; genetics
5.The construction of a novel recombinant virus Δ67R-RGV and preliminary analyses the function of the 67R gene.
Xing HUANG ; Chao PEI ; Li-Bo HE ; Qi-Ya ZHANG
Chinese Journal of Virology 2014;30(5):495-501
The Rana grylio virus (RGV) is a member of the genus Ranavirus. It belongs to the family Iridoviridae, and contains the gene 67R encoding dUTPase. In order to investigate the function of 67R in the replication and infection of RGV, we constructed Δ67R-RGV, a recombinant virus with deletion of 67R. First, we constructed the plasmid pGL3-67RL-p50-EGFP-67RR which carried an enhanced green fluorescence gene (EGFP) as a selectable marker. After homologous recombination between pGL3-67RL-p50-EG- FP-67RR and the RGV genome, Epithelioma papulosum cyprini (EPC) cells were infected with the resulting mixture. Through ten successive rounds of plaque isolation via EGFP selection, all plaques emitted green fluorescence, and finally Δ67R-RGV was generated. Total DNA of Δ67R-RGV infected cells was extracted for PCR analyses. Simulateously, mock infected and wild-type RGV (wt-RGV) infected cells were used as a comparison. Results showed that 67R could be detected in wt-RGV infected cells, but that only the EGFP gene was detected in Δ67R-RGV infected cells. Furthermore, one-step growth curves of wt-RGV and Δ67R-RGV were similar. Therefore, 67R and its encoding product dUTPase might not be essential for the growth of RGV. These results suggest that, homologous recombination and recombinant rana- virus could be used to study the gene function of viruses in aquatic animals.
Genes, Viral
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physiology
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Genome, Viral
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Polymerase Chain Reaction
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Pyrophosphatases
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genetics
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Ranavirus
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genetics
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Recombination, Genetic
8.Gene optimization is necessary to express HPV type 6 L1 protein in the methylotrophic yeast Pichia pastoris.
Ping-chuan LI ; Xiao-guang ZHANG ; Ling ZHOU ; Yi ZENG
Chinese Journal of Experimental and Clinical Virology 2003;17(4):310-314
OBJECTIVEHuman papillomavirus 6 (HPV 6) causes genital warts, a common sexually transmitted disease. L1-capsids protein is a highly promising vaccine candidate that has entered phase II clinical trial. But the existing methodologies for producing L1-capsids in insect cells is expensive for use in developing countries. As methylotrophic yeast,the Pichia pastoris expression system offers economy,and high expression levels. Over-expression of HPV6-L1 protein in P. pastoris was the purpose of this study.
METHODSThe whole L1 gene with preferred codons for P. pastoris was rebuilt and A-T rich regions were abolished, Cloning into pPIC3.5K,electroporation of KM71, in vivo screen of multiple inserts by G418 resistance, PCR analysis of pichia integrants, BMGY/BMMY are used for induction and expression of L1 proteins.
RESULTSThree clones were found to produce L1 protein which can be identified with Western blot. Compared with L1 protein from E.coli, pichia-produced L1 has some glycosylation. Reacting strongly with MabH6B10.5 in indirect immunofluorescence assay indicated that L1 protein expressed in pichia cell holds its native conformational epitopes which is important for vaccine use. A total 125 microg pure L1 protein could be obtained from 1L cultures through ion-exchange and Ni-NTA chromatography.
CONCLUSIONHPV type 6 L1 protein expressed in Pichia pastoris will facilitate the HPV vaccine development and structure-function study.
Capsid Proteins ; biosynthesis ; genetics ; isolation & purification ; Cloning, Molecular ; Genes ; Papillomaviridae ; genetics ; Pichia ; genetics ; metabolism ; Viral Proteins
9.Analysis of B/C recombinant structure of C gene in a newly found HBV subtype.
Qing-Qing YI ; Lei MA ; Qi-Nan JIA ; Jian-Feng HE
Chinese Journal of Virology 2014;30(1):19-24
Hepatitis B is one of the most serious global threats to human health. Phylogenetic analysis of hepatitis B virus (HBV) can reveal the evolutionary relationship between HBV sequences and thus provide a basis for the prediction and treatment of hepatitis B and other aspects. In this study, we performed sequence analyses on the HBV sequences of five clinical HBV samples and the HBV sequences retrieved from the GenBank, EMBL, and DDBJ to construct a phylogenetic tree and analyze sequence structures. The experimental results revealed that the C gene of one cloned sequence had a recombinant structure of HBV B/ C subtype. Moreover, the phylogenetic results proved the existence of a newly found subtype HBV/B6 in Xishuangbanna of Yunnan Province, China. The experimental conclusion represents certain value for phylogenetic studies of HBV in Yunnan ethnic minority groups.
DNA, Recombinant
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genetics
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Genes, Viral
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genetics
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Genotyping Techniques
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Hepatitis B virus
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classification
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genetics
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Humans
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Phylogeny
10.Avirulence genes of plant pathogens.
Xin-Zhong CAI ; You-Ping XU ; Zhong ZHENG
Chinese Journal of Biotechnology 2002;18(1):5-9
One type of important plant disease resistance, gene-for-gene resistance, is resulted from the interactions between products of the pathogen avirulence (Avr) genes and their matching plant resistance (R) genes. Avr genes have been cloned from a variety of pathogens including fungi, bacteria, viruses and oomycetes. No significant homology is found between sequences of the most cloned Avr genes and those of known proteins or between those of themselves. However, significant homology has been found between sequences of the cloned R genes and those of known proteins or between those of themselves. R proteins consist of similar domains. It has been reported that hypersensitive cell death and resistance, which are induced by interactions between products of different Avr/R gene pairs consisting of similar R genes but different Avr genes, are distinct in development speed, strength, and organ and tissue specificity. Avr genes have dual functions: Pathogens containing Avr genes are avirulent to plants carrying the matching R genes, while they are virulent in race, strain, pathovar or species-specific way to plants without carrying the matching R genes.
Bacteria
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genetics
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pathogenicity
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Fungi
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genetics
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pathogenicity
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Gene Expression
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Genes, Bacterial
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physiology
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Genes, Fungal
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physiology
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Genes, Viral
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physiology
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Plant Diseases
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genetics
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microbiology
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virology
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Plant Viruses
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genetics
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pathogenicity
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Virulence