title: Microevolution of bank voles (Myodes glareolus) at neutral and immune-related genes during multiannual dynamic cycles: Consequences for Puumala hantavirus epidemiology.
abstract: Understanding how host dynamics, including variations of population size and dispersal, may affect the epidemiology of infectious diseases through ecological and evolutionary processes is an active research area. Here we focus on a bank vole (Myodes glareolus) metapopulation surveyed in Finland between 2005 and 2009. Bank vole is the reservoir of Puumala hantavirus (PUUV), the agent of nephropathia epidemica (NE, a mild form of hemorrhagic fever with renal symptom) in humans. M. glareolus populations experience multiannual density fluctuations that may influence the level of genetic diversity maintained in bank voles, PUUV prevalence and NE occurrence. We examine bank vole metapopulation genetics at presumably neutral markers and immune-related genes involved in susceptibility to PUUV (Tnf-promoter, Tlr4, Tlr7 and Mx2 gene) to investigate the links between population dynamics, microevolutionary processes and PUUV epidemiology. We show that genetic drift slightly and transiently affects neutral and adaptive genetic variability within the metapopulation. Gene flow seems to counterbalance its effects during the multiannual density fluctuations. The low abundance phase may therefore be too short to impact genetic variation in the host, and consequently viral genetic diversity. Environmental heterogeneity does not seem to affect vole gene flow, which might explain the absence of spatial structure previously detected in PUUV in this area. Besides, our results suggest the role of vole dispersal on PUUV circulation through sex-specific and density-dependent movements. We find little evidence of selection acting on immune-related genes within this metapopulation. Footprint of positive selection is detected at Tlr-4 gene in 2008 only. We observe marginally significant associations between Mx2 genotype and PUUV genogroups. These results show that neutral processes seem to be the main factors affecting the evolution of these immune-related genes at a contemporary scale, although the relative effects of neutral and adaptive forces could vary temporally with density fluctuations. Immune related gene polymorphism may in turn partly influence PUUV epidemiology in this metapopulation.
authors.affiliation: INRA, UMR CBGP, F-34988 Montferrier-sur-Lez, France; Anses, Unité de Virologie, 31 avenue Tony Garnier, 69364 Lyon, France. Electronic address: adelaide.dubois@supagro.inra.fr.
authors.forename: Adelaïde
authors.initials: A
authors.lastname: Dubois
authors.affiliation: INRA, UMR CBGP, F-34988 Montferrier-sur-Lez, France.
authors.forename: Maxime
authors.initials: M
authors.lastname: Galan
authors.affiliation: INRA, UMR CBGP, F-34988 Montferrier-sur-Lez, France; INRA-ANSES-ENVA, UMR 0956 BIPAR, Maisons-Alfort, France.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Cosson
authors.affiliation: INRA, USC1339 (CEBC-CNRS), Villiers en Bois F-79360, France.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Gauffre
authors.affiliation: Natural Resources Institute Finland, FI-013012 Vantaa, Finland.
authors.forename: Heikki
authors.initials: H
authors.lastname: Henttonen
authors.affiliation: Natural Resources Institute Finland, FI-013012 Vantaa, Finland.
authors.forename: Jukka
authors.initials: J
authors.lastname: Niemimaa
authors.affiliation: INRA, UMR CBGP, F-34988 Montferrier-sur-Lez, France.
authors.forename: Maria
authors.initials: M
authors.lastname: Razzauti
authors.affiliation: Natural Resources Institute Finland, FI-013012 Vantaa, Finland; Department of Virology, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Liina
authors.initials: L
authors.lastname: Voutilainen
authors.affiliation: INRA, UMR CBGP, F-34988 Montferrier-sur-Lez, France.
authors.forename: Renaud
authors.initials: R
authors.lastname: Vitalis
authors.affiliation: Biogeosciences, CNRS UMR 6282, Université de Bourgogne, Franche-Comté, 21000, Dijon, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Guivier
authors.affiliation: INRA, UMR CBGP, F-34988 Montferrier-sur-Lez, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Charbonnel
mesh_terms: D000818:Animals; D003411:Arvicolinae / Q000276:immunology / Q000821:virology*; D005075:Biological Evolution; D004197:Disease Reservoirs / Q000821:virology*; D004198:Disease Susceptibility; D005260:Female; D005387:Finland / Q000453:epidemiology; D015870:Gene Expression / Q000276:immunology*; D051456:Gene Flow; D040961:Genetic Drift; D006480:Hemorrhagic Fever with Renal Syndrome / Q000453:epidemiology / Q000235:genetics / Q000276:immunology / Q000662:veterinary*; D054884:Host-Pathogen Interactions; D006801:Humans; D008297:Male; D017720:Molecular Epidemiology; D064547:Myxovirus Resistance Proteins / Q000235:genetics / Q000276:immunology; D011110:Polymorphism, Genetic; D011157:Population Dynamics; D029262:Puumala virus / Q000254:growth & development / Q000472:pathogenicity; D012376:Rodent Diseases / Q000453:epidemiology* / Q000235:genetics / Q000276:immunology / Q000821:virology; D051197:Toll-Like Receptor 4 / Q000235:genetics / Q000276:immunology; D051199:Toll-Like Receptor 7 / Q000235:genetics / Q000276:immunology
chemical_list: D064547:Myxovirus Resistance Proteins; D051197:Toll-Like Receptor 4; D051199:Toll-Like Receptor 7
keywords: Adaptation; Density fluctuations; Host-pathogen interaction; Immunogenetics; Population genetics; Rodent