LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 4 of total 4

Search options

  1. Article: Fitness Estimation for Viral Variants in the Context of Cellular Coinfection

    Zhu, Huisheng / Allman, Brent E. / Koelle, Katia

    Viruses. 2021 June 23, v. 13, no. 7

    2021  

    Abstract: Animal models are frequently used to characterize the within-host dynamics of emerging zoonotic viruses. More recent studies have also deep-sequenced longitudinal viral samples originating from experimental challenges to gain a better understanding of ... ...

    Abstract Animal models are frequently used to characterize the within-host dynamics of emerging zoonotic viruses. More recent studies have also deep-sequenced longitudinal viral samples originating from experimental challenges to gain a better understanding of how these viruses may evolve in vivo and between transmission events. These studies have often identified nucleotide variants that can replicate more efficiently within hosts and also transmit more effectively between hosts. Quantifying the degree to which a mutation impacts viral fitness within a host can improve identification of variants that are of particular epidemiological concern and our ability to anticipate viral adaptation at the population level. While methods have been developed to quantify the fitness effects of mutations using observed changes in allele frequencies over the course of a host’s infection, none of the existing methods account for the possibility of cellular coinfection. Here, we develop mathematical models to project variant allele frequency changes in the context of cellular coinfection and, further, integrate these models with statistical inference approaches to demonstrate how variant fitness can be estimated alongside cellular multiplicity of infection. We apply our approaches to empirical longitudinally sampled H5N1 sequence data from ferrets. Our results indicate that previous studies may have significantly underestimated the within-host fitness advantage of viral variants. These findings underscore the importance of considering the process of cellular coinfection when studying within-host viral evolutionary dynamics.
    Keywords alleles ; gene frequency ; mixed infection ; mutation ; statistical inference
    Language English
    Dates of publication 2021-0623
    Publishing place Multidisciplinary Digital Publishing Institute
    Document type Article
    ZDB-ID 2516098-9
    ISSN 1999-4915
    ISSN 1999-4915
    DOI 10.3390/v13071216
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

  2. Article ; Online: Fitness Estimation for Viral Variants in the Context of Cellular Coinfection.

    Zhu, Huisheng / Allman, Brent E / Koelle, Katia

    Viruses

    2021  Volume 13, Issue 7

    Abstract: Animal models are frequently used to characterize the within-host dynamics of emerging zoonotic viruses. More recent studies have also deep-sequenced longitudinal viral samples originating from experimental challenges to gain a better understanding of ... ...

    Abstract Animal models are frequently used to characterize the within-host dynamics of emerging zoonotic viruses. More recent studies have also deep-sequenced longitudinal viral samples originating from experimental challenges to gain a better understanding of how these viruses may evolve in vivo and between transmission events. These studies have often identified nucleotide variants that can replicate more efficiently within hosts and also transmit more effectively between hosts. Quantifying the degree to which a mutation impacts viral fitness within a host can improve identification of variants that are of particular epidemiological concern and our ability to anticipate viral adaptation at the population level. While methods have been developed to quantify the fitness effects of mutations using observed changes in allele frequencies over the course of a host's infection, none of the existing methods account for the possibility of cellular coinfection. Here, we develop mathematical models to project variant allele frequency changes in the context of cellular coinfection and, further, integrate these models with statistical inference approaches to demonstrate how variant fitness can be estimated alongside cellular multiplicity of infection. We apply our approaches to empirical longitudinally sampled H5N1 sequence data from ferrets. Our results indicate that previous studies may have significantly underestimated the within-host fitness advantage of viral variants. These findings underscore the importance of considering the process of cellular coinfection when studying within-host viral evolutionary dynamics.
    MeSH term(s) Animals ; Coinfection/virology ; Evolution, Molecular ; Ferrets ; Gene Frequency ; Genetic Fitness ; Humans ; Influenza A Virus, H5N1 Subtype/genetics ; Models, Genetic ; Mutation ; Orthomyxoviridae Infections/virology
    Language English
    Publishing date 2021-06-23
    Publishing country Switzerland
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 2516098-9
    ISSN 1999-4915 ; 1999-4915
    ISSN (online) 1999-4915
    ISSN 1999-4915
    DOI 10.3390/v13071216
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  3. Article ; Online: Hitchhiking in space: Ancestry in adapting, spatially extended populations.

    Allman, Brent E / Weissman, Daniel B

    Evolution; international journal of organic evolution

    2018  Volume 72, Issue 4, Page(s) 722–734

    Abstract: Selective sweeps reduce neutral genetic diversity. In sexual populations, this "hitchhiking" effect is thought to be limited to the local genomic region of the sweeping allele. While this is true in panmictic populations, we find that in spatially ... ...

    Abstract Selective sweeps reduce neutral genetic diversity. In sexual populations, this "hitchhiking" effect is thought to be limited to the local genomic region of the sweeping allele. While this is true in panmictic populations, we find that in spatially extended populations the combined effects of many unlinked sweeps can affect patterns of ancestry (and therefore neutral genetic diversity) across the whole genome. Even low rates of sweeps can be enough to skew the spatial locations of ancestors such that neutral mutations that occur in an individual living outside a small region in the center of the range have virtually no chance of fixing in the population. The fact that nearly all ancestry rapidly traces back to a small spatial region also means that relatedness between individuals falls off very slowly as a function of the spatial distance between them.
    MeSH term(s) Alleles ; Evolution, Molecular ; Genetic Variation ; Models, Genetic ; Mutation ; Selection, Genetic
    Language English
    Publishing date 2018-02-13
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2036375-8
    ISSN 1558-5646 ; 0014-3820
    ISSN (online) 1558-5646
    ISSN 0014-3820
    DOI 10.1111/evo.13431
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  4. Article ; Online: Assessing the direct and indirect effects of food provisioning and nutrient enrichment on wildlife infectious disease dynamics.

    Civitello, David J / Allman, Brent E / Morozumi, Connor / Rohr, Jason R

    Philosophical transactions of the Royal Society of London. Series B, Biological sciences

    2018  Volume 373, Issue 1745

    Abstract: Anthropogenic resource supplementation can shape wildlife disease directly by altering the traits and densities of hosts and parasites or indirectly by stimulating prey, competitor or predator species. We first assess the direct epidemiological ... ...

    Abstract Anthropogenic resource supplementation can shape wildlife disease directly by altering the traits and densities of hosts and parasites or indirectly by stimulating prey, competitor or predator species. We first assess the direct epidemiological consequences of supplementation, highlighting the similarities and differences between food provisioning and two widespread forms of nutrient input: agricultural fertilization and aquatic nutrient enrichment. We then review an aquatic disease system and a general model to assess whether predator and competitor species can enhance or overturn the direct effects of enrichment. All forms of supplementation can directly affect epidemics by increasing host population size or altering parasite production within hosts, but food provisioning is most likely to aggregate hosts and increase parasite transmission. However, if predators or competitors increase in response to supplementation, they could alter resource-fuelled outbreaks in focal hosts. We recommend identifying the traits of hosts, parasites or interacting species that best predict epidemiological responses to supplementation and evaluating the relative importance of these direct and indirect mechanisms. Theory and experiments should examine the timing of behavioural, physiological and demographic changes for realistic, variable scenarios of supplementation. A more integrative view of resource supplementation and wildlife disease could yield broadly applicable disease management strategies.This article is part of the theme issue 'Anthropogenic resource subsidies and host-parasite dynamics in wildlife'.
    MeSH term(s) Animals ; Chlorophyta/microbiology ; Competitive Behavior/physiology ; Daphnia/microbiology ; Fish Diseases/epidemiology ; Fish Diseases/microbiology ; Fish Diseases/transmission ; Fishes/microbiology ; Fishes/physiology ; Food Chain ; Host-Pathogen Interactions ; Humans ; Metschnikowia/growth & development ; Metschnikowia/pathogenicity ; Models, Statistical ; Mycoses/epidemiology ; Mycoses/microbiology ; Mycoses/transmission ; Mycoses/veterinary ; Predatory Behavior/physiology ; Spores, Fungal/growth & development ; Spores, Fungal/pathogenicity
    Language English
    Publishing date 2018-03-12
    Publishing country England
    Document type Journal Article ; Research Support, U.S. Gov't, Non-P.H.S. ; Review
    ZDB-ID 208382-6
    ISSN 1471-2970 ; 0080-4622 ; 0264-3839 ; 0962-8436
    ISSN (online) 1471-2970
    ISSN 0080-4622 ; 0264-3839 ; 0962-8436
    DOI 10.1098/rstb.2017.0101
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

To top