na gene
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2022 ◽  
Author(s):  
Meghan Diefenbacher ◽  
Timothy J.C. Tan ◽  
David L.V. Bauer ◽  
Beth Stadtmueller ◽  
Nicholas C. Wu ◽  
...  

The influenza A virus (IAV) genome is divided into eight negative-sense, single-stranded RNA segments. Each segment exhibits a unique level and temporal pattern of expression, however the exact mechanisms underlying the patterns of individual gene segment expression are poorly understood. We previously demonstrated that a single substitution in the viral nucleoprotein (NP:F346S) selectively modulates neuraminidase (NA) gene segment expression while leaving other segments largely unaffected. Given what is currently known about NP function, there is no obvious explanation for how changes in NP can selectively modulate the replication of individual gene segments. We found that the specificity of this effect for the NA segment is virus strain specific and depends on the UTR sequences of the NA segment. While the NP:F346S substitution did not significantly alter the RNA binding or oligomerization activities of NP in vitro, it specifically decreased the ability of NP to promote NA segment vRNA synthesis. In addition to NP residue F346, we identified two other adjacent aromatic residues in NP (Y385 & F479) capable of similarly regulating NA gene segment expression, suggesting a larger role for this domain in gene-segment specific regulation. Our findings reveal a new role for NP in selective regulation of viral gene segment replication and demonstrate how the expression patterns of individual viral gene segments can be modulated during adaptation to new host environments.


Pathogens ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1527
Author(s):  
Andreja Jungić ◽  
Vladimir Savić ◽  
Josip Madić ◽  
Ljubo Barbić ◽  
Besi Roić ◽  
...  

In a total of 1536 blood serum samples analysed by ELISA, antibodies for IAV nucleoprotein (NP) were detected in 30.3%. Results from HI show that the most common subtype of swIAV in the Croatian pig population was H1N1 (44.6%), followed by H3N2 (42.7%) and H1N2 (26.3%). Antibodies to at least one subtype were detected in 62.19% of blood serum samples. Detection of swIAV antigen was performed by IHC and detected in 8 of 28 lung samples collected post-mortem. The matrix (M) gene was detected in nine of one hundred and forty-two lung tissue samples and in seven of twenty-nine nasopharyngeal swabs. Phylogenetic analysis of amplified HA and NA gene fragments in Croatian isolates suggests the presence of swIAV H1avN1av.


Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2208
Author(s):  
Mohamed Tarek ◽  
Mahmoud M. Naguib ◽  
Abdel-Sattar Arafa ◽  
Laila A. Tantawy ◽  
Karim M. Selim ◽  
...  

Highly pathogenic avian influenza (HPAI) viruses of subtype H5N8 continue to circulate, causing huge economic losses and serious impact on poultry production worldwide. Recently, HPAIV H5N8 has been spreading rapidly, and a large number of HPAI H5N8 outbreaks have been reported in Eurasia 2020–2021. In this study, we conducted an epidemiological survey of HPAI H5N8 virus at different geographical locations in Egypt from 2017 to 2019. This was followed by genetic and pathogenic studies. Our findings highlight the wide spread of HPAI H5N8 viruses in Egypt, including in 22 governorates. The genetic analyses of the hemagglutinin (HA) and neuraminidase (NA) gene segments emphasized a phylogenetic relatedness between the Egyptian HPAI H5N8 viruses and viruses of clade 2.3.4.4b recently isolated in Europe. These findings suggest that a potential back transmission of Egyptian HPAI H5N8 virus has occurred from domestic poultry in Egypt to migratory wild birds, followed by further spread to different countries. This highlights the importance of continuous epidemiological and genetic studies of AIVs at the domestic–wild bird interface.


2021 ◽  
Vol 34 (1) ◽  
pp. 25-31
Author(s):  
S. O. Peters ◽  
C. O. N Ikeobi ◽  
M. O. Ozoje ◽  
O. A. Famakinwa ◽  
Y. S. Oshodi ◽  
...  

An investigations was carried out to determine the effect of the major genes of frizzling and naked neck on the external and internal egg quality traits of the Nigerian local chicken. Egg weight significantly (P < 0.01) favoured the frizzled local chicken and the naked-necked local chicken over the fully feathered (normal ) local chicken. The frizzling gene, F, caused an increase of 8.13% in weight while the naked neck gene Na, increased egg weight by 5.85%. The Na gene caused the production of better egg shape index (0.73) when compared to F and nana, ff genotypes. Eggs of frizzed and naked-neck locals also had significantly (P < 0.05) better Haugh unit, percent shell, percent albumen and percent yolk than the normal feathered counterpart. It is therefore reasonable to incorporate the major genes frizzling and naked-neck in producing a locally-adapter commercial egg strain


2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Yafen Liu ◽  
Yue Wang ◽  
Baiyi Liu ◽  
Xu Cong ◽  
Ying Ji ◽  
...  

Abstract Background Influenza A(H1N1)pdm09 viruses have undergone rapid evolution, and in recent years the complementary and antagonistic effects of HA and NA have gathered more attentions; however, the effects of co-occurring mutations in HA and NA on the patients’ clinical characteristics are still poorly understood. In this study, we analyzed molecular epidemiology and evolution of A(H1N1) pdm09, explored co-occurring mutations of HA and NA, and investigated effect of co-occurring mutations on patients’ clinical features. Methods A(H1N1)pdm09 was confirmed by reverse transcription-polymerase chain reaction. HA and NA genes were sequenced and phylogenetically analyzed. Clinical characteristics of the co-occurring mutations were analyzed statistically. Results By analyzing the HA and NA gene sequences of 33 A(H1N1)pdm09 viruses during the 2015–2017 influenza season, we found that all the viruses shared high similarities to each other and the HA genes of these viruses exclusively belonged to subclade 6B.1A. Several unreported substitutions in HA and NA proteins were observed, furthermore, co-occurring mutations of HA-V169T, A278S, E508G, D518E and NA-V67I were detected in 30.3% (10/33) A(H1N1)pdm09 virus strains when comparing with vaccine strains A/California/07/2009 and A/Michigan/45/2015 (H1N1). Sore throat was significantly associated with co-occurring mutations in HA and NA of A(H1N1)pdm09 (χ2, P < 0.05). Conclusions Co-occurring mutations in HA and NA were detected in A(H1N1)pdm09 isolated during 2015–2017 in Beijing. Symptomatically, sore throat was associated with co-occurring mutations in HA and NA of A(H1N1)pdm09. Therefore, studying the effect and mechanism of co-occurring mutations in HA and NA on patients’ clinical features is of note needed.


2020 ◽  
Author(s):  
Yafen Liu ◽  
Yue Wang ◽  
Baiyi Liu ◽  
Xu Cong ◽  
Ying Ji ◽  
...  

Abstract Background: Influenza A(H1N1)pdm09 viruses have undergone rapid evolution, and in recent years the complementary and antagonistic effects of HA and NA have gathered more attentions; however, the effects of co-occurring mutations in HA and NA on the patients’ clinical characteristics are still poorly understood. In this study, we analyzed molecular epidemiology and evolution of A(H1N1) pdm09, explored co-occurring mutations of HA and NA, and investigated effect of co-occurring mutations on patients’ clinical features.Methods: A(H1N1)pdm09 was confirmed by reverse transcription-polymerase chain reaction. HA and NA genes were sequenced and phylogenetically analyzed. Clinical characteristics of the co-occurring mutations were analyzed statistically.Results: By analyzing the HA and NA gene sequences of 33 A(H1N1)pdm09 viruses during the 2015-2017 influenza season, we found that all the viruses shared high similarities to each other and the HA genes of these viruses exclusively belonged to subclade 6B.1A. Several unreported substitutions in HA and NA proteins were observed, furthermore, co-occurring mutations of HA-V169T, A278S, E508G, D518E and NA-V67I were detected in 30.3% (10/33) A(H1N1)pdm09 virus strains when comparing with vaccine strains A/California/07/2009 and A/Michigan/45/2015 (H1N1). Sore throat was significantly associated with co-occurring mutations in HA and NA of A(H1N1)pdm09 (χ2, P < 0.05).Conclusions: Co-occurring mutations in HA and NA were detected in A(H1N1)pdm09 isolated during 2015-2017 in Beijing. Symptomatically, sore throat was associated with co-occurring mutations in HA and NA of A(H1N1)pdm09. Therefore, studying the effect and mechanism of co-occurring mutations in HA and NA on patients’ clinical features is of note needed.


2020 ◽  
Author(s):  
Yafen Liu ◽  
Yue Wang ◽  
Baiyi Liu ◽  
Xu Cong ◽  
Ying Ji ◽  
...  

Abstract Background Influenza A(H1N1)pdm09 viruses have undergone rapid evolution, and in recent years the complementary and antagonistic effects of HA and NA have gathered more attentions; however, the effects of co-occurring mutations in HA and NA on the patients’ clinical characteristics are still poorly understood. In this study, we analyzed molecular epidemiology and evolution of A(H1N1) pdm09, explored co-occurring mutations of HA and NA, and investigated effect of co-occurring mutations on patients’ clinical features. Methods A(H1N1)pdm09 was confirmed by reverse transcription-polymerase chain reaction. HA and NA genes were sequenced and phylogenetically analyzed. Clinical characteristics of the co-occurring mutations were analyzed statistically. Results By analyzing the HA and NA gene sequences of 33 A(H1N1)pdm09 viruses during the 2015–2017 influenza season, we found that all the viruses shared high similarities to each other and the HA genes of these viruses exclusively belonged to subclade 6B.1A. Several new substitutions of HA and NA exhibited in the new sites, furthermore, co-occurring mutations of HA-V169T, A278S, E508G, D518E and NA-V67I were detected in 30.3% (10/33) A(H1N1)pdm09 virus strains when comparing with vaccine strains A/California/07/2009 and A/Michigan/45/2015 (H1N1). Sore throat was significantly associated with co-occurring mutations in HA and NA of A(H1N1)pdm09 (χ2, P < 0.05). Conclusions Co-occurring mutations in HA and NA were detected in A(H1N1)pdm09 isolated during 2015–2017 in Beijing. Symptomatically, sore throat was associated with co-occurring mutations in HA and NA of A(H1N1)pdm09. Therefore, studying the effect and mechanism of co-occurring mutations in HA and NA on patients’ clinical features is of note needed.


2019 ◽  
Author(s):  
Nahla M. Saeed ◽  
Peshnyar M.A. Rashid ◽  
Hiewa Othman Dyary

Abstract After the circulation of H5N1 in 2006, 2015 and 2016 in Iraq, a new H5N8 influenza virus emerged in Iraq in 2018. In this study, a HPAI virus subtype H5N8 was identified from backyard domestic geese in Kurdistan region, Iraq. Phylogenic analyses of the hemagglutinin (HA) and neuraminidase (NA) genes indicated that Iraq H5N8 viruses belonged to clade 2.3.4.4 group B and clustered with isolates from Iran, Israel and Belgium. Genetic analysis of HA of the Iraq H5N8 indicated molecular markers for avian-type receptors. Characterization of the NA gene showed that the virus had sensitive molecular markers for antiviral drugs. This is the first study ever on H5N8 in Iraq and it is crucial to understand the epidemiology of the viruses in Iraq and the Middle East. The results are suggestive of a possible role of migratory birds in the introduction of HPAI subtype H5N8 into Iraq.


2019 ◽  
Author(s):  
Nahla M. Saeed ◽  
Peshnyar M.A. Rashid ◽  
Hiewa Othman Dyary

Abstract After the circulation of H5N1 in 2006, 2015 and 2016 in Iraq, a new H5N8 influenza virus emerged in Iraq in 2018. In this study, a HPAI virus subtype H5N8 was identified from backyard domestic geese in Kurdistan region, Iraq. Phylogenic analyses of the hemagglutinin (HA) and neuraminidase (NA) genes indicated that Iraq H5N8 viruses belonged to clade 2.3.4.4 group B and clustered with isolates from Iran, Israel and Belgium. Genetic analysis of HA of the Iraq H5N8 indicated molecular markers for avian-type receptors. Characterization of the NA gene showed that the virus had sensitive molecular markers for antiviral drugs. This is the first study ever on H5N8 in Iraq and it is crucial to understand the epidemiology of the viruses in Iraq and the Middle East. The results are suggestive of a possible role of migratory birds in the introduction of HPAI subtype H5N8 into Iraq.


2019 ◽  
Vol 79 (1) ◽  
pp. 61-74 ◽  
Author(s):  
Jingkai Hu ◽  
Yunfeng Zha ◽  
Xuanjiang Jin ◽  
Xiaohui Wen ◽  
Zhixian Li ◽  
...  

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