H9N2 avian influenza virus（AIV） infection is a major problem in poultry industry worldwide. In this study, molecular characterizations and phylogenetic relationships of hemagglutinin（HA） gene sequences of H9N2 AIV...H9N2 avian influenza virus（AIV） infection is a major problem in poultry industry worldwide. In this study, molecular characterizations and phylogenetic relationships of hemagglutinin（HA） gene sequences of H9N2 AIV of 5 Chinese isolates in 2014 recently available in Gen Bank, 3 widely used vaccine strains, and 52 novel isolates in China from 2013 to 2015 were analyzed. The homology analysis showed that the nucleotide sequences of HA gene of these recent Chinese H9N2 AIV isolates shared homologies from 94.1 to 99.9%. Phylogenetic analysis showed that all isolates belonged to AIV lineage h9.4.2.5. Fifty-six out of the 57 recent Chinese H9N2 AIV isolates had the motifs PSRSSR↓GLF at the cleavage sites within the HA protein, while one isolate PWH01 harbored LSRSSR↓GLF. Remarkably, all of the recent Chinese H9N2 AIV strains had the Q216 L substitution in the receptor binding site, which indicated that they had potential to infect humans. Most of recent Chinese H9N2 AIV isolates lost the potential N-linked glycosylation site at residues 200–202 compared with vaccine strains. This present study demonstrated that AIV lineage h9.4.2.5 was more predominant in China than other lineages as it harbored all the H9N2 AIV isolated between 2013 and 2015. Also we showed the importance of continuous surveillance of emerging H9N2 AIV in China and update of vaccine formulation accordingly in order to prevent and control H9N2 AIV.展开更多
Hemagglutinin gene of Measles virus(Nepal strain) was amplified by RT PCR technique, cloned and sequenced by the dideoxy mediated chain termination method. The comparison to the standard strain(Edmonston strain) sho...Hemagglutinin gene of Measles virus(Nepal strain) was amplified by RT PCR technique, cloned and sequenced by the dideoxy mediated chain termination method. The comparison to the standard strain(Edmonston strain) showed many important mutations. The homology of these two strains was 98.17%. Then H gene was cloned into expression vector pCD SRα296 and introduced into COS 7 cells by electroporation method. The expression and function of cloned H gene was checked by hemadsorption assays.展开更多
A mutation network for the hemagglutinin gene(HA) of the novel type A(H1N1) influenza virus was constructed.Sequence homology analysis indicated that one HA sequence type from the viruses mainly isolated from Mexico w...A mutation network for the hemagglutinin gene(HA) of the novel type A(H1N1) influenza virus was constructed.Sequence homology analysis indicated that one HA sequence type from the viruses mainly isolated from Mexico was likely the original type in this epidemic.Based on the 658A and 1408T mutations in HA,the viruses evolving into this epidemic were divided into three categories,the Mexico,the transitional and the New York type.The three groups of viruses presented distinctive clustering features in their geographic distributions.展开更多
[ Objective] To determine the HA gene sequences of four H9N2 Avian influenza virus （AIV） strains and carry out comparative analysis so as to understand the difference and variation pattern of each strain from the an...[ Objective] To determine the HA gene sequences of four H9N2 Avian influenza virus （AIV） strains and carry out comparative analysis so as to understand the difference and variation pattern of each strain from the angle of molecular biology and to know the distribution and epidemic law of H9N2 AIV. [Method] One pair of primers was designed referring to HA gene sequences of H9N2 AIV. The HA genes of A/Chicken/Hebei/WD/98 （H9N2; WD98 for short）, A/Chicken/Hebei/ZD/04 （H9N2; ZD04 for short））, A/Chicken/Beijing/MY/06 （H9N2; MY06 for short） ）, and A/Chicken/Beijing/PG/08 （H9N2; PG08 for short）） were amplified, cloned and sequenced. Then the HA gene sequences of these strains were compared with that of 10 H9N2 AIV stains in GenBank. [Result] The ORF of HA genes of the four strains was 1 683 bp in size, encoding 516 amino acids. The HA gene sequences of the four strains, WD98, MY06, PG08, and ZD04, were 82.6% -95.1%, 83.0% -99.0%, 82.7% -95.5%, and 81.3% -95.7% homologous to that of the 10 H9N2 AIV stains, respectively. And the homology of amino acid was respectively 86.6% -96.3%, 86.6% -97.9%, 87.0% -97.1%, and 86.9% -97.3%. [ Conclusion] The HA gene has greatly high homology among different strains.展开更多
RT-PCR was employed to amplify the cDNA of HA gene of influenza A/Chicken/Guangdong/SS/94(H 9N 2)with a pair of degenerate primers and the cDNA were cloned into the T-T windows of plasmid pMD18-T.The inserts were sequ...RT-PCR was employed to amplify the cDNA of HA gene of influenza A/Chicken/Guangdong/SS/94(H 9N 2)with a pair of degenerate primers and the cDNA were cloned into the T-T windows of plasmid pMD18-T.The inserts were sequenced,at first time,and the results revealed that the HA gene had a long complete open reading frame and composed of 1,683 nucleotides,coding for 560 amino acids.The amino acid sequences of the HA connecting peptide revealed that A/Chicken/Guangdong/SS/94(H 9N 2)had X-X-X-R(X,not basic amino acid)at the proteolytic cleavage site.The molecular basis of the HA gene was compatible with not highly pathogenicity.Comparison of the degree of homology of HA gene showed 82%-98% nucleotide sequence and amino acid sequence homology among the isolate and the other H 9N 2 subtype AIV in GenBank. Thus, the HA gene of influenza A/Chicken/Guangdong/SS/94 belonged to H 9 subtype.展开更多
The complete cDNA sequences of HA genes of two AIV isolates were presented in this paper The result of comparative sequence analysis seemed to suggest that these two isolates may be identical to three other AIV strain...The complete cDNA sequences of HA genes of two AIV isolates were presented in this paper The result of comparative sequence analysis seemed to suggest that these two isolates may be identical to three other AIV strains(H 9N 2) isolated from HongKong recently and these five strains may have the same origin in that the identity of the HA protein sequences of these AIV isolates is higher than 95%展开更多
Six isolates of Newcastle disease virus were derived from south and east China regions during the disease outbreaks called "avian paramyxovirus infection of geese" or "geese paramyxovirus infection"...Six isolates of Newcastle disease virus were derived from south and east China regions during the disease outbreaks called "avian paramyxovirus infection of geese" or "geese paramyxovirus infection",and partial sequence analysis of hemagglutinin-neuraminidase(HN) gene was carried out to identify the genetic characteristics of these goose isolatesA 1905 nucleotide portion of HN gene of each of the 6 isolates was sequenced,the results revealed that the coding region of their HN genes are all 1716 nucleotides in length,which can encode 571 amino acid residues aloneThe coding region is followed by a noncoding sequence of 189 nucleotidesThough they diverged only 08%-37% from each other in the nucleotide sequences of coding region,they differed by 175%-179% to F48E8, a standard challenge strain of chicken originCysteine residues are well conserved throughout the amino acid sequences,while the number of the potential glycosylation sites varys from 4 to 6Residue positions Thr 48,His 54,Ser 77,Ala 266,His 340 and Lys 384 are also highly conserved in the 6 goose isolatesThe corresponding residues in other NDV strains are commonly Met 48,Ser 54,Asn 77,Ile 266,Tyr 340 and Glu 384However,the sequences of receptor-binding related regions show no difference to the 14 reference strains from domestic or展开更多
基金supported by the National Modern Agricultural Industry Technology System Project of China(CARS-41)the Science and Technology Plan Project of Guangdong Province,China(2012B020306002 and 2012B091100078)
文摘H9N2 avian influenza virus（AIV） infection is a major problem in poultry industry worldwide. In this study, molecular characterizations and phylogenetic relationships of hemagglutinin（HA） gene sequences of H9N2 AIV of 5 Chinese isolates in 2014 recently available in Gen Bank, 3 widely used vaccine strains, and 52 novel isolates in China from 2013 to 2015 were analyzed. The homology analysis showed that the nucleotide sequences of HA gene of these recent Chinese H9N2 AIV isolates shared homologies from 94.1 to 99.9%. Phylogenetic analysis showed that all isolates belonged to AIV lineage h9.4.2.5. Fifty-six out of the 57 recent Chinese H9N2 AIV isolates had the motifs PSRSSR↓GLF at the cleavage sites within the HA protein, while one isolate PWH01 harbored LSRSSR↓GLF. Remarkably, all of the recent Chinese H9N2 AIV strains had the Q216 L substitution in the receptor binding site, which indicated that they had potential to infect humans. Most of recent Chinese H9N2 AIV isolates lost the potential N-linked glycosylation site at residues 200–202 compared with vaccine strains. This present study demonstrated that AIV lineage h9.4.2.5 was more predominant in China than other lineages as it harbored all the H9N2 AIV isolated between 2013 and 2015. Also we showed the importance of continuous surveillance of emerging H9N2 AIV in China and update of vaccine formulation accordingly in order to prevent and control H9N2 AIV.
文摘Hemagglutinin gene of Measles virus(Nepal strain) was amplified by RT PCR technique, cloned and sequenced by the dideoxy mediated chain termination method. The comparison to the standard strain(Edmonston strain) showed many important mutations. The homology of these two strains was 98.17%. Then H gene was cloned into expression vector pCD SRα296 and introduced into COS 7 cells by electroporation method. The expression and function of cloned H gene was checked by hemadsorption assays.
文摘A mutation network for the hemagglutinin gene(HA) of the novel type A(H1N1) influenza virus was constructed.Sequence homology analysis indicated that one HA sequence type from the viruses mainly isolated from Mexico was likely the original type in this epidemic.Based on the 658A and 1408T mutations in HA,the viruses evolving into this epidemic were divided into three categories,the Mexico,the transitional and the New York type.The three groups of viruses presented distinctive clustering features in their geographic distributions.
基金Supported by subproject of Major State Basic Research Development Program of China (2005CB523001)~~
文摘[ Objective] To determine the HA gene sequences of four H9N2 Avian influenza virus （AIV） strains and carry out comparative analysis so as to understand the difference and variation pattern of each strain from the angle of molecular biology and to know the distribution and epidemic law of H9N2 AIV. [Method] One pair of primers was designed referring to HA gene sequences of H9N2 AIV. The HA genes of A/Chicken/Hebei/WD/98 （H9N2; WD98 for short）, A/Chicken/Hebei/ZD/04 （H9N2; ZD04 for short））, A/Chicken/Beijing/MY/06 （H9N2; MY06 for short） ）, and A/Chicken/Beijing/PG/08 （H9N2; PG08 for short）） were amplified, cloned and sequenced. Then the HA gene sequences of these strains were compared with that of 10 H9N2 AIV stains in GenBank. [Result] The ORF of HA genes of the four strains was 1 683 bp in size, encoding 516 amino acids. The HA gene sequences of the four strains, WD98, MY06, PG08, and ZD04, were 82.6% -95.1%, 83.0% -99.0%, 82.7% -95.5%, and 81.3% -95.7% homologous to that of the 10 H9N2 AIV stains, respectively. And the homology of amino acid was respectively 86.6% -96.3%, 86.6% -97.9%, 87.0% -97.1%, and 86.9% -97.3%. [ Conclusion] The HA gene has greatly high homology among different strains.
文摘RT-PCR was employed to amplify the cDNA of HA gene of influenza A/Chicken/Guangdong/SS/94(H 9N 2)with a pair of degenerate primers and the cDNA were cloned into the T-T windows of plasmid pMD18-T.The inserts were sequenced,at first time,and the results revealed that the HA gene had a long complete open reading frame and composed of 1,683 nucleotides,coding for 560 amino acids.The amino acid sequences of the HA connecting peptide revealed that A/Chicken/Guangdong/SS/94(H 9N 2)had X-X-X-R(X,not basic amino acid)at the proteolytic cleavage site.The molecular basis of the HA gene was compatible with not highly pathogenicity.Comparison of the degree of homology of HA gene showed 82%-98% nucleotide sequence and amino acid sequence homology among the isolate and the other H 9N 2 subtype AIV in GenBank. Thus, the HA gene of influenza A/Chicken/Guangdong/SS/94 belonged to H 9 subtype.
文摘The complete cDNA sequences of HA genes of two AIV isolates were presented in this paper The result of comparative sequence analysis seemed to suggest that these two isolates may be identical to three other AIV strains(H 9N 2) isolated from HongKong recently and these five strains may have the same origin in that the identity of the HA protein sequences of these AIV isolates is higher than 95%
文摘Six isolates of Newcastle disease virus were derived from south and east China regions during the disease outbreaks called "avian paramyxovirus infection of geese" or "geese paramyxovirus infection",and partial sequence analysis of hemagglutinin-neuraminidase(HN) gene was carried out to identify the genetic characteristics of these goose isolatesA 1905 nucleotide portion of HN gene of each of the 6 isolates was sequenced,the results revealed that the coding region of their HN genes are all 1716 nucleotides in length,which can encode 571 amino acid residues aloneThe coding region is followed by a noncoding sequence of 189 nucleotidesThough they diverged only 08%-37% from each other in the nucleotide sequences of coding region,they differed by 175%-179% to F48E8, a standard challenge strain of chicken originCysteine residues are well conserved throughout the amino acid sequences,while the number of the potential glycosylation sites varys from 4 to 6Residue positions Thr 48,His 54,Ser 77,Ala 266,His 340 and Lys 384 are also highly conserved in the 6 goose isolatesThe corresponding residues in other NDV strains are commonly Met 48,Ser 54,Asn 77,Ile 266,Tyr 340 and Glu 384However,the sequences of receptor-binding related regions show no difference to the 14 reference strains from domestic or
