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12 results on '"viral population dynamics"'

1. Higher HIV-1 genetic diversity is associated with AIDS and neuropsychological impairment

Author

Hightower, George K, Wong, Joseph K, Letendre, Scott L, Umlauf, Anya A, Ellis, Ronald J, Ignacio, Caroline C, Heaton, Robert K, Collier, Ann C, Marra, Christina M, Clifford, David B, Gelman, Benjamin B, McArthur, Justin C, Morgello, Susan, Simpson, David M, McCutchan, JA, Grant, Igor, Little, Susan J, Richman, Douglas D, Pond, Sergei L Kosakovsky, Smith, Davey M, and Group, the CHARTER Study

Subjects
Biological Sciences, Biomedical and Clinical Sciences, Genetics, Human Genome, Infectious Diseases, Sexually Transmitted Infections, HIV/AIDS, Mental Health, Acquired Immunodeficiency Syndrome, Adult, Cohort Studies, Female, Genes, pol, Genetic Variation, HIV Infections, HIV-1, Humans, Male, Middle Aged, Neuropsychological Tests, RNA, Viral, HIV, AIDS, Genetic diversity, Neuropsychological impairment, Viral population dynamics, CHARTER Study Group, Agricultural and Veterinary Sciences, Medical and Health Sciences, Virology, Agricultural, veterinary and food sciences, Biological sciences, Biomedical and clinical sciences
Abstract

Standard methods used to estimate HIV-1 population diversity are often resource intensive (e.g., single genome amplification, clonal amplification and pyrosequencing) and not well suited for large study cohorts. Additional approaches are needed to address the relationships between intraindividual HIV-1 genetic diversity and 2 disease. With a small cohort of individuals, we validated three methods for measuring diversity: Shannon entropy and average pairwise distance (APD) using single genome sequences, and counts of mixed bases (i.e. ambiguous nucleotides) from population based sequences. In a large cohort, we then used the mixed base approach to determine associations between measure HIV-1 diversity and HIV associated disease. Normalized counts of mixed bases correlated with Shannon Entropy at both the nucleotide (rho=0.72, p=0.002) and amino acid level (rho=0.59, p=0.015), and APD (rho=0.75, p=0.001). Among participants who underwent neuropsychological and clinical assessments (n=187), increased HIV-1 population diversity was associated with both a diagnosis of AIDS and neuropsychological impairment.

Published
2012

2. Rapid Dissemination and Monopolization of Viral Populations in Mice Revealed Using a Panel of Barcoded Viruses.

Author

McCune, Broc T., Lanahan, Matthew R., tenOever, Benjamin R., and Pfeiffer, Julie K.

Subjects
*POPULATION dynamics, *INTESTINAL infections, *VIRAL genomes, *VIRUSES, *MICE, *COXSACKIEVIRUSES, *ENTEROVIRUSES, *VIRAL antibodies
Abstract

The gastrointestinal tract presents a formidable barrier for pathogens to initiate infection. Despite this barrier, enteroviruses, including coxsackievirus B3 (CVB3), successfully penetrate the intestine to initiate infection and spread systemically prior to shedding in stool. However, the effect of the gastrointestinal barrier on CVB3 population dynamics is relatively unexplored, and the selective pressures acting on CVB3 in the intestine are not well characterized. To examine viral population dynamics in orally infected mice, we produced over 100 CVB3 clones harboring nine unique nucleotide "barcodes." Using this collection of barcoded viruses, we found diverse viral populations throughout each mouse within the first day postinfection, but by 48 h the viral populations were dominated by fewer than three barcoded viruses in intestinal and extraintestinal tissues. Using light-sensitive viruses to track replication status, we found that diverse viruses had replicated prior to loss of diversity. Sequencing whole viral genomes from samples later in infection did not reveal detectable viral adaptations. Surprisingly, orally inoculated CVB3 was detectable in pancreas and liver as soon as 20 min postinoculation, indicating rapid systemic dissemination. These results suggest rapid dissemination of diverse viral populations, followed by a major restriction in population diversity and monopolization in all examined tissues. These results underscore a complex dynamic between dissemination and clearance for an enteric virus. [ABSTRACT FROM AUTHOR]

Published
2020
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3. Phylogenetic Structure and Sequential Dominance of Sub-Lineages of PRRSV Type-2 Lineage 1 in the United States

Author

Igor A. D. Paploski, Nakarin Pamornchainavakul, Dennis N. Makau, Albert Rovira, Cesar A. Corzo, Declan C. Schroeder, Maxim C-J. Cheeran, Andrea Doeschl-Wilson, Rowland R. Kao, Samantha Lycett, and Kimberly VanderWaal

Subjects
porcine reproductive and respiratory syndrome virus, phylogenetic analysis, principal component analyses, mutations, viral population dynamics, whole genome, Medicine
Abstract

The genetic diversity and frequent emergence of novel genetic variants of porcine reproductive and respiratory syndrome virus type-2 (PRRSV) hinders control efforts, yet drivers of macro-evolutionary patterns of PRRSV remain poorly documented. Utilizing a comprehensive database of >20,000 orf5 sequences, our objective was to classify variants according to the phylogenetic structure of PRRSV co-circulating in the U.S., quantify evolutionary dynamics of sub-lineage emergence, and describe potential antigenic differences among sub-lineages. We subdivided the most prevalent lineage (Lineage 1, accounting for approximately 60% of available sequences) into eight sub-lineages. Bayesian coalescent SkyGrid models were used to estimate each sub-lineage’s effective population size over time. We show that a new sub-lineage emerged every 1 to 4 years and that the time between emergence and peak population size was 4.5 years on average (range: 2–8 years). A pattern of sequential dominance of different sub-lineages was identified, with a new dominant sub-lineage replacing its predecessor approximately every 3 years. Consensus amino acid sequences for each sub-lineage differed in key GP5 sites related to host immunity, suggesting that sub-lineage turnover may be linked to immune-mediated competition. This has important implications for understanding drivers of genetic diversity and emergence of new PRRSV variants in the U.S.

Published
2021
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4. Phylogenetic Structure and Sequential Dominance of Sub-Lineages of PRRSV Type-2 Lineage 1 in the United States

Author

Andrea Doeschl-Wilson, Igor A.D. Paploski, Declan C. Schroeder, Dennis N. Makau, Kimberly VanderWaal, Rowland R. Kao, Samantha Lycett, Maxim C.-J. Cheeran, Nakarin Pamornchainavakul, Albert Rovira, and Cesar Corzo

Subjects
0301 basic medicine, principal component analyses, 040301 veterinary sciences, Lineage (evolution), animal diseases, viruses, Immunology, Biology, Article, Coalescent theory, 0403 veterinary science, multi-strain dynamics, 03 medical and health sciences, Effective population size, PHYLOGENETIC DIVERSITY, Drug Discovery, Pharmacology (medical), Evolutionary dynamics, viral population dynamics, Pharmacology, Genetic diversity, Phylogenetic tree, whole genome, Population size, phylogenetic analysis, virus diseases, 04 agricultural and veterinary sciences, respiratory system, porcine reproductive and respiratory syndrome virus, mutations, Phylogenetic diversity, 030104 developmental biology, Infectious Diseases, Evolutionary biology, Medicine, human activities
Abstract

The genetic diversity and frequent emergence of novel genetic variants of porcine reproductive and respiratory syndrome virus type-2 (PRRSV) hinders control efforts, yet drivers of macro-evolutionary patterns of PRRSV remain poorly documented. Utilizing a comprehensive database of &gt, 20,000 orf5 sequences, our objective was to classify variants according to the phylogenetic structure of PRRSV co-circulating in the U.S., quantify evolutionary dynamics of sub-lineage emergence, and describe potential antigenic differences among sub-lineages. We subdivided the most prevalent lineage (Lineage 1, accounting for approximately 60% of available sequences) into eight sub-lineages. Bayesian coalescent SkyGrid models were used to estimate each sub-lineage’s effective population size over time. We show that a new sub-lineage emerged every 1 to 4 years and that the time between emergence and peak population size was 4.5 years on average (range: 2–8 years). A pattern of sequential dominance of different sub-lineages was identified, with a new dominant sub-lineage replacing its predecessor approximately every 3 years. Consensus amino acid sequences for each sub-lineage differed in key GP5 sites related to host immunity, suggesting that sub-lineage turnover may be linked to immune-mediated competition. This has important implications for understanding drivers of genetic diversity and emergence of new PRRSV variants in the U.S.

Published
2021
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5. Diversity and dynamics of bacteriophages in horse feces.

Author

Kulikov, E. E., Isaeva, A. S., Rotkina, A. S., Manykin, A. A., and Letarov, A. V.

Subjects
*BACTERIOPHAGES, *FECES, *HORSES, *INTESTINES, *RUMINANTS
Abstract

The complex cellulolytic microbial community of the horse intestines is a convenient model for studying the ecology of bacteriophages in natural habitats. Unlike the rumen of the ruminants, this community of the equine large intestine is not subjected to digestion. The inner conditions of the horse gut are much more stable in comparison to other mammals, due to the fact that the horse diet remains almost unchanged and the intervals between food consumption and defecation are much shorter than the whole digestive cycle. The results of preliminary analysis of the structure and dynamics of the viral community of horse feces, which combines direct and culture methods, are presented. In horse fecal samples, we detected more than 60 morphologically distinct phage types, the majority of which were present as a single phage particle. This indicates that the community includes no less than several hundreds of phage types. Some phage types dominated and constituted 5–11% of the total particle count each. The most numerous phage type had an unusual morphology: the tails of its members were extremely long (about 700 nm), flexible, and irretractable, while their heads were 100 nm in diameter. Several other phage types with similar but not identical properties were detected. The total coliphage plaque count of the samples taken from three animals revealed significant fluctuations in the phage titers. During the observation time, the maximum titer ranged within four orders of magnitude (103-107 plaque forming units (PFU)/g); the minimum titer ranged within two orders of magnitude. The samples contained two to five morphologically distinct and potentially competitive coliphage types, specific to a single Escherichia coli strain. [ABSTRACT FROM AUTHOR]

Published
2007
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6. Phylogenetic Structure and Sequential Dominance of Sub-Lineages of PRRSV Type-2 Lineage 1 in the United States.

Author

Paploski, Igor A. D., Pamornchainavakul, Nakarin, Makau, Dennis N., Rovira, Albert, Corzo, Cesar A., Schroeder, Declan C., Cheeran, Maxim C-J., Doeschl-Wilson, Andrea, Kao, Rowland R., Lycett, Samantha, and VanderWaal, Kimberly

Subjects
PORCINE reproductive & respiratory syndrome, GENETIC variation, AMINO acid sequence, SOCIAL dominance, ACTINOBACILLUS pleuropneumoniae
Abstract

The genetic diversity and frequent emergence of novel genetic variants of porcine reproductive and respiratory syndrome virus type-2 (PRRSV) hinders control efforts, yet drivers of macro-evolutionary patterns of PRRSV remain poorly documented. Utilizing a comprehensive database of >20,000 orf5 sequences, our objective was to classify variants according to the phylogenetic structure of PRRSV co-circulating in the U.S., quantify evolutionary dynamics of sub-lineage emergence, and describe potential antigenic differences among sub-lineages. We subdivided the most prevalent lineage (Lineage 1, accounting for approximately 60% of available sequences) into eight sub-lineages. Bayesian coalescent SkyGrid models were used to estimate each sub-lineage's effective population size over time. We show that a new sub-lineage emerged every 1 to 4 years and that the time between emergence and peak population size was 4.5 years on average (range: 2–8 years). A pattern of sequential dominance of different sub-lineages was identified, with a new dominant sub-lineage replacing its predecessor approximately every 3 years. Consensus amino acid sequences for each sub-lineage differed in key GP5 sites related to host immunity, suggesting that sub-lineage turnover may be linked to immune-mediated competition. This has important implications for understanding drivers of genetic diversity and emergence of new PRRSV variants in the U.S. [ABSTRACT FROM AUTHOR]

Published
2021
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8. Higher HIV-1 genetic diversity is associated with AIDS and neuropsychological impairment

Author

Davey M. Smith, George K. Hightower, Joseph K. Wong, Ann C. Collier, David M. Simpson, Susan Morgello, Ronald J. Ellis, Scott Letendre, Benjamin B. Gelman, David B. Clifford, Douglas D. Richman, Robert K. Heaton, Justin C. McArthur, Christina M. Marra, Igor Grant, Susan J. Little, McCutchan Ja, Sergei L. Kosakovsky Pond, Caroline Ignacio, and Anya Umlauf

Subjects
Adult, Male, HIV Infections, Disease, Neuropsychological Tests, Biology, Genome, Article, Genetic diversity, Cohort Studies, Acquired immunodeficiency syndrome (AIDS), Virology, Genetic variation, medicine, Humans, Neuropsychological impairment, Genetics, Acquired Immunodeficiency Syndrome, Viral population dynamics, Genetic Variation, HIV, Middle Aged, medicine.disease, Genes, pol, AIDS, Cohort, HIV-1, RNA, Viral, Pyrosequencing, Female, Cohort study
Abstract

Standard methods used to estimate HIV-1 population diversity are often resource intensive (e.g., single genome amplification, clonal amplification and pyrosequencing) and not well suited for large study cohorts. Additional approaches are needed to address the relationships between intraindividual HIV-1 genetic diversity and 2 disease. With a small cohort of individuals, we validated three methods for measuring diversity: Shannon entropy and average pairwise distance (APD) using single genome sequences, and counts of mixed bases (i.e. ambiguous nucleotides) from population based sequences. In a large cohort, we then used the mixed base approach to determine associations between measure HIV-1 diversity and HIV associated disease. Normalized counts of mixed bases correlated with Shannon Entropy at both the nucleotide (rho=0.72, p=0.002) and amino acid level (rho=0.59, p=0.015), and APD (rho=0.75, p=0.001). Among participants who underwent neuropsychological and clinical assessments (n=187), increased HIV-1 population diversity was associated with both a diagnosis of AIDS and neuropsychological impairment.

Published
2012

9. Protection of the durability of major resistance genes to plant viruses with quantitative resistance, a modeling approach

Author

Rousseau, Elsa, Coville, Jerome, Palloix, Alain, Fabre, Frédéric, Mailleret, Ludovic, Moury, Benoît, Grognard, Frédéric, Station de Pathologie Végétale (AVI-PATHO), Institut National de la Recherche Agronomique (INRA), Biological control of artificial ecosystems (BIOCORE), Institut National de la Recherche Agronomique (INRA)-Inria Sophia Antipolis - Méditerranée (CRISAM), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire d'océanographie de Villefranche (LOV), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire océanologique de Villefranche-sur-mer (OOVM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire océanologique de Villefranche-sur-mer (OOVM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Biostatistique et Processus Spatiaux (BIOSP), Unité de recherche Génétique et amélioration des fruits et légumes (GALF), Unité Mixte de Recherche en Santé Végétale (INRA/ENITA) (UMR SAVE), Institut National de la Recherche Agronomique (INRA)-École Nationale d'Ingénieurs des Travaux Agricoles - Bordeaux (ENITAB)-Institut des Sciences de la Vigne et du Vin (ISVV), Institut Sophia Agrobiotech [Sophia Antipolis] (ISA), Institut National de la Recherche Agronomique (INRA)-Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Observatoire océanologique de Villefranche-sur-mer (OOVM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire océanologique de Villefranche-sur-mer (OOVM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Unité de recherche Génétique et amélioration des fruits et légumes (GAFL), COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'océanographie de Villefranche (LOV), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Inria Sophia Antipolis - Méditerranée (CRISAM), and Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de la Recherche Agronomique (INRA)

Subjects
[SPI]Engineering Sciences [physics], quantitative resistance, selection advantage, [MATH.MATH-GM]Mathematics [math]/General Mathematics [math.GM], durable resistance, [INFO.INFO-AU]Computer Science [cs]/Automatic Control Engineering, [SDV]Life Sciences [q-bio], fungi, food and beverages, genetic drift, viral population dynamics
Abstract

International audience; The deployment of virus-resistant crops often leads to the emergence of resistance-breaking (RB) pathogens that suppress the yield benefit provided by the resistance. Although breakdowns are well known for plant genes conferring total, i.e. qualitative, resistance to the virus, they are still poorly understood for plant genetic factors conferring partial, i.e. quantitative resistance. Furthermore, it has been proved for several pathosystems that combining qualitative and quantitative resistances can increase the durability of the qualitative resistance. Two mechanisms can explain this result : either (i) an increase of genetic drift in the virus population, or (ii) a decrease of the selection advantage of the RB mutant. Here, we aim at disentangling the role of these two mechanisms on the durability of plant qualitative resistances to viruses. To investigate this, we follow by high-throughput sequencing the within-host demo-genetic dynamics of five Potato virus Y (PVY) variants in sixteen contrasted pepper plant genotypes, carrying a qualitative resistance and different combinations of quantitative resistances. PVY variants carry distinct mutations, each mutation conferring weak to strong adaptation to the qualitative resistance. We measure the within-host virus variants frequencies and the relative virus population size at different time points. We estimate the fitness of each virus variant by fitting a Lotka-Volterra model of competition between variants to these data. We assess the strength of genetic drift by analysing and modeling between-host variances of the variants frequencies at each time point. With this modeling approach, we can determine how quantitative resistance can increase the durability of qualitative resistance, and provide criteria to screen host genotypes with sustainable pathogen resistance.

Published
2014

10. Protection of the durability of major resistance genes to plant viruses through quantitative resistance, a modeling approach

Author

Rousseau, Elsa, Coville, Jérôme, Fabre, Frédéric, Mailleret, Ludovic, Palloix, Alain, Moury, Benoît, Grognard, Frédéric, Institut Sophia Agrobiotech (ISA), Institut National de la Recherche Agronomique (INRA)-Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), Unité de Pathologie Végétale (PV), Institut National de la Recherche Agronomique (INRA), Biological control of artificial ecosystems (BIOCORE), Laboratoire d'océanographie de Villefranche (LOV), Observatoire océanologique de Villefranche-sur-mer (OOVM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire océanologique de Villefranche-sur-mer (OOVM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Inria Sophia Antipolis - Méditerranée (CRISAM), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de la Recherche Agronomique (INRA), Biostatistique et Processus Spatiaux (BioSP), Santé et agroécologie du vignoble (UMR SAVE), Institut National de la Recherche Agronomique (INRA)-Université de Bordeaux (UB)-Institut des Sciences de la Vigne et du Vin (ISVV)-Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro), Génétique et Amélioration des Fruits et Légumes (GAFL), Centre National de la Recherche Scientifique (CNRS)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut National de la Recherche Agronomique (INRA), Institut National de la Recherche Agronomique (INRA)-Inria Sophia Antipolis - Méditerranée (CRISAM), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire d'océanographie de Villefranche (LOV), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Observatoire océanologique de Villefranche-sur-mer (OOVM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Observatoire océanologique de Villefranche-sur-mer (OOVM), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDV.SA]Life Sciences [q-bio]/Agricultural sciences, selection advantage, quantitative resistance, durable resistance, [MATH.MATH-ST]Mathematics [math]/Statistics [math.ST], fungi, food and beverages, genetic drift, [MATH]Mathematics [math], viral population dynamics
Abstract

International audience; The deployment of virus-resistant crops often leads to the emergence of resistance-breaking (RB) pathogens that suppress the yield benefit provided by the resistance [1]. Although break- downs are well known for plant genes conferring total, i.e. qualitative resistance to the virus, they are still poorly understood for plant genetic factors conferring partial, i.e. quantitative resistance. Furthermore, it has been proved for several pathosystems that combining qualita- tive and quantitative resistances can increase the durability of the qualitative resistance [2, 3]. Two mechanisms can explain this result : either (i) an increase of genetic drift in the virus population, or (ii) a decrease of the selection advantage of the RB mutant. Here, we aim at disentangling the role of these two mechanisms on the durability of plant qualitative resistances to viruses.

Published
2014

11. Protection of the durability of major resistance genes to plant viruses through quantitative resistance, a modeling approach

Author

Coville, Jérôme, Fabre, Frédéric, Mailleret, Ludovic, Palloix, Alain, Moury, Benoit, Grognard, Frédéric, and Rousseau, Elsa

Subjects
virus phytopathogène, résistance quantitative, dérive génétique, fungi, quantitative resistance, genetic drift, selection advantage, viral population dynamics, durable resistance, food and beverages, avantage sélectif, maladie des plantes, Agricultural sciences, durabilité des résistances, résistance qualitative, évolution génétique des populations, résistance durable, sélection variétale, Sciences agricoles
Abstract

The deployment of virus-resistant crops often leads to the emergence of resistance-breaking (RB) pathogens that suppress the yield benefit provided by the resistance [1]. Although break- downs are well known for plant genes conferring total, i.e. qualitative resistance to the virus, they are still poorly understood for plant genetic factors conferring partial, i.e. quantitative resistance. Furthermore, it has been proved for several pathosystems that combining qualita- tive and quantitative resistances can increase the durability of the qualitative resistance [2, 3]. Two mechanisms can explain this result : either (i) an increase of genetic drift in the virus population, or (ii) a decrease of the selection advantage of the RB mutant. Here, we aim at disentangling the role of these two mechanisms on the durability of plant qualitative resistances to viruses.

Published
2014

12. West Nile Virus Fitness Costs in Different Mosquito Species.

Author

Coffey, Lark L. and Reisen, William K.

Subjects
*WEST Nile virus, *PUBLIC health, *EPIDEMICS, *GENOTYPES, *ANIMAL species
Abstract

West Nile virus (WNV) remains an important public health problem causing annual epidemics in the United States. Grubaugh et al . observed that WNV genetic divergence is dependent on the vector mosquito species. This suggests that specific WNV vector–bird species pairings may generate novel genotypes that could promote outbreaks. [ABSTRACT FROM AUTHOR]

Published
2016
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