Quantification of intrahost bottlenecks of West Nile virus in Culex pipiens mosquitoes using an artificial mutant swarm

• Published in: Infection, genetics and evolution Vol. 12; no. 3; pp. 557 - 564
• Main Authors: Ciota, Alexander T., Ehrbar, Dylan J., Van Slyke, Greta A., Payne, Anne F., Willsey, Graham G., Viscio, Rachael E., Kramer, Laura D.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01.04.2012; Elsevier
• Subjects: Adaptation, Biological; Animals; Arbovirus evolution; Biological and medical sciences; Chlorocebus aethiops; Cloning, Molecular; Culex; Culex - growth & development; Culex - physiology; Culex - virology; Culex pipiens; DNA, Viral; DNA, Viral - genetics; Epidemiology. Vaccinations; Evolution, Molecular; Feeding Behavior; Flavivirus; General aspects; genetics; growth & development; Host-Pathogen Interactions; hosts; Infectious diseases; Insect Vectors; Insect Vectors - virology; Intrahost bottlenecks; Intrahost diversity; Medical sciences; midgut; mutants; pathogenicity; pathogens; physiology; RNA; Salivary Glands; Salivary Glands - virology; space and time; Stochastic Processes; Time Factors; Vero Cells; Viral Load; virology; Virus Replication; viruses; West Nile virus; West Nile virus - genetics; West Nile virus - growth & development; West Nile virus - pathogenicity; West Nile virus - physiology; Intrahost diversity; Culex pipiens; Arbovirus evolution; Intrahost bottlenecks; Flavivirus; West Nile virus; Insecta; Virus; Infection; Arthropoda; Culicidae; Molecular epidemiology; Evolution; Japanese encephalitis group virus; Flaviviridae; Invertebrata; Arbovirus; Diptera; Quantitative analysis
• ISSN: 1567-1348; 1567-7257; 1567-7257
• DOI: 10.1016/j.meegid.2012.01.022

► An artificial mutant swarm of neutral West Nile virus variants was created. ► Changes to mutant swarm breadth in Culexpipiens were tracked over time and space. ► A stochastic narrowing of the mutant swarm was measured over time during infection. ► Significant decreases in swarm breadth occur with midgut infection and transmission. ► Results demonstrate the probability of variant survival during mosquito infection. Mosquito-borne viruses are predominantly RNA viruses which exist within hosts as diverse mutant swarms. Defining the way in which stochastic forces within mosquito vectors shape these swarms is critical to advancing our understanding of the evolutionary and adaptive potential of these pathogens. There are multiple barriers within a mosquito which a viral swarm must traverse in order to ultimately be transmitted. Here, using artificial mutant swarms composed of neutral variants of West Nile virus (WNV), we tracked changes to swarm breadth over time and space in Culex pipiens mosquitoes. Our results demonstrate that all variants have the potential to survive intrahost bottlenecks, yet mean swarm breadth decreases during both midgut infection and transmission when starting populations contain higher levels of minority variants. In addition, WNV swarms are subject to temporal sweeps which act to significantly decrease intrahost diversity over time. Taken together, these data demonstrate the profound effects that stochastic forces can have in shaping arboviral mutant swarms.