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Basic Characteristics of Mutations
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Mutation Site
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T156A |
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Mutation Site Sentence
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Among mutations that emerged during mouse-adaptation, we focused on amino acid substitutions in polymerase subunits: polymerase basic-1 (PB1) T156A and F740L and polymerase acidic (PA) E349G. |
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Mutation Level
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Amino acid level |
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Mutation Type
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Nonsynonymous substitution |
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Gene/Protein/Region
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PB1 |
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Standardized Encoding Gene
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PB1
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Genotype/Subtype
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H1N1 |
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Viral Reference
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NC_026438;FJ969531;NC_026437;FJ981613;NC_026436;GQ377078;FJ969527;NC_026432
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Functional Impact and Mechanisms
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Disease
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Influenza A
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Immune
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- |
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Target Gene
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-
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Clinical and Epidemiological Correlations
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Clinical Information
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- |
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Treatment
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- |
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Location
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America |
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Literature Information
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PMID
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29783694
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Title
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Adaptive Mutations in Influenza A/California/07/2009 Enhance Polymerase Activity and Infectious Virion Production
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Author
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Slaine PD,MacRae C,Kleer M,Lamoureux E,McAlpine S,Warhuus M,Comeau AM,McCormick C,Hatchette T,Khaperskyy DA
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Journal
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Viruses
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Journal Info
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2018 May 18;10(5):272
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Abstract
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Mice are not natural hosts for influenza A viruses (IAVs), but they are useful models for studying antiviral immune responses and pathogenesis. Serial passage of IAV in mice invariably causes the emergence of adaptive mutations and increased virulence. Here, we report the adaptation of IAV reference strain A/California/07/2009(H1N1) (also known as CA/07) in outbred Swiss Webster mice. Serial passage led to increased virulence and lung titers, and dissemination of the virus to brains. We adapted a deep-sequencing protocol to identify and enumerate adaptive mutations across all genome segments. Among mutations that emerged during mouse-adaptation, we focused on amino acid substitutions in polymerase subunits: polymerase basic-1 (PB1) T156A and F740L and polymerase acidic (PA) E349G. These mutations were evaluated singly and in combination in minigenome replicon assays, which revealed that PA E349G increased polymerase activity. By selectively engineering three PB1 and PA mutations into the parental CA/07 strain, we demonstrated that these mutations in polymerase subunits decreased the production of defective viral genome segments with internal deletions and dramatically increased the release of infectious virions from mouse cells. Together, these findings increase our understanding of the contribution of polymerase subunits to successful host adaptation.
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Sequence Data
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MG027911;MG027912;MG027913;MG027914;MG027915
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