title: Importance of mosquito "quasispecies" in selecting an epidemic arthropod-borne virus.
abstract: Most arthropod-borne viruses (arboviruses), perpetuated by alternation between a vertebrate host and an insect vector, are likely to emerge through minor genetic changes enabling the virus to adapt to new hosts. In the past decade, chikungunya virus (CHIKV; Alphavirus, Togaviridae) has emerged on La Réunion Island following the selection of a unique substitution in the CHIKV E1 envelope glycoprotein (E1-A226V) of an East-Central-South African (ECSA) genotype conferring a higher transmission rate by the mosquito Aedes albopictus. Assumed to have occurred independently on at least four separate occasions, this evolutionary convergence was suspected to be responsible for CHIKV worldwide expansion. However, assumptions on CHIKV emergence were mainly based on viral genetic changes and the role of the mosquito population quasispecies remained unexplored. Here we show that the nature of the vector population is pivotal in selecting the epidemic CHIKV. We demonstrate using microsatellites mosquito genotyping that Ae. albopictus populations are genetically differentiated, contributing to explain their differential ability to select the E1-226V mutation. Aedes albopictus, newly introduced in Congo coinciding with the first CHIKV outbreak, was not able to select the substitution E1-A226V nor to preferentially transmit a CHIKV clone harboring the E1-226V as did Ae. albopictus from La Réunion.
authors.affiliation: Department of Virology, Institut Pasteur, Arboviruses and Insect Vectors, 75724 Paris cedex 15, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Vazeille
authors.affiliation: Department of Virology, Institut Pasteur, Arboviruses and Insect Vectors, 75724 Paris cedex 15, France.
authors.forename: Karima
authors.initials: K
authors.lastname: Zouache
authors.affiliation: Department of Virology, Institut Pasteur, Arboviruses and Insect Vectors, 75724 Paris cedex 15, France.|Institut Pasteur of Guadeloupe, Laboratory of Medical Entomology, Environment and Health, Guadeloupe, BP 484, Morne Jolivière, 97183 Abymes, Guadeloupe.
authors.forename: Anubis
authors.initials: A
authors.lastname: Vega-Rúa
authors.affiliation: Department of Infection and Epidemiology, Institut Pasteur, Environment and Infectious Risks/Laboratory for Urgent Response to Biological Threats (CIBU), Pole of Pathogen Genotyping, 75724 Paris cedex 15, France.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Thiberge
authors.affiliation: Department of Infection and Epidemiology, Institut Pasteur, Environment and Infectious Risks/Laboratory for Urgent Response to Biological Threats (CIBU), Pole of Pathogen Genotyping, 75724 Paris cedex 15, France.
authors.forename: Valérie
authors.initials: V
authors.lastname: Caro
authors.affiliation: Centre de Démoustication/Conseil général de La Martinique, 97234 Fort-de-France, Martinique.
authors.forename: André
authors.initials: A
authors.lastname: Yébakima
authors.affiliation: Department of Virology, Institut Pasteur, Arboviruses and Insect Vectors, 75724 Paris cedex 15, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Mousson
authors.affiliation: Aix Marseille Université, IRD French Institute of Research for Development, EHESP French School of Public Health, EPV UMR_D 190 'Emergence des Pathologies Virales', 13005 Marseille cedex 05, France.|IHU Méditerranée Infection, APHM Public Hospitals of Marseille, 13385 Marseille cedex 05,France.
authors.forename: Géraldine
authors.initials: G
authors.lastname: Piorkowski
authors.affiliation: Center for Bioinformatics, BioStatistics and Integrative Biology, International Group for Data Analysis, 75724 Paris cedex 15, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Dauga
authors.affiliation: Department of Virology, Institut Pasteur, Structural Virology, 75724 Paris cedex 15, France.
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Vaney
authors.affiliation: Department of Biology and Biotechnology "Lazzaro Spallanzani", Laboratorio degli insetti di interesse agrario e sanitario,Università degli Studi di Pavia, Viale Ferrata 9, 27100, Pavia, Italy.
authors.forename: Mosè
authors.initials: M
authors.lastname: Manni
authors.affiliation: Department of Biology and Biotechnology "Lazzaro Spallanzani", Laboratorio degli insetti di interesse agrario e sanitario,Università degli Studi di Pavia, Viale Ferrata 9, 27100, Pavia, Italy.
authors.forename: Giuliano
authors.initials: G
authors.lastname: Gasperi
authors.affiliation: Aix Marseille Université, IRD French Institute of Research for Development, EHESP French School of Public Health, EPV UMR_D 190 'Emergence des Pathologies Virales', 13005 Marseille cedex 05, France.|IHU Méditerranée Infection, APHM Public Hospitals of Marseille, 13385 Marseille cedex 05,France.
authors.forename: Xavier
authors.initials: X
authors.lastname: de Lamballerie
authors.affiliation: Department of Virology, Institut Pasteur, Arboviruses and Insect Vectors, 75724 Paris cedex 15, France.
authors.forename: Anna-Bella
authors.initials: AB
authors.lastname: Failloux
mesh_terms: D000330:Aedes / Q000235:genetics* / Q000821:virology*; D000818:Animals; D065632:Chikungunya Fever / Q000635:transmission* / Q000821:virology; D002646:Chikungunya virus / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D002522:Chlorocebus aethiops; D003223:Congo; D005260:Female; D005347:Fibroblasts / Q000821:virology; D014644:Genetic Variation; D005828:Genetics, Population; D006801:Humans; D000072138:Mosquito Vectors / Q000821:virology*; D010802:Phylogeny; D017508:Reunion; D014709:Vero Cells; D019562:Viral Load