title: Additional heritable virus in the parasitic wasp Leptopilina boulardi: prevalence, transmission and phenotypic effects.
abstract: Parasitoid wasps can be found in association with heritable viruses. Although some viruses have been shown to profoundly affect the biology and evolution of parasitoid wasps, the genetic and phenotypic diversity of parasitoid-associated viruses remains largely unexplored. We previously discovered a behaviour-manipulating DNA virus in the parasitoid wasp Leptopilina boulardi. In this species, which lays its eggs inside Drosophila larvae, Leptopilina boulardi filamentous virus (LbFV) forces the females to lay their eggs in already parasitized Drosophila larvae. This behavioural manipulation increases the chances for the horizontal transmission of the virus. Here, we describe in the same parasitoid species another virus, which we propose to call Leptopilina boulardi toti-like virus (LbTV). This double-stranded RNA virus is highly prevalent in insect laboratory lines as well as in parasitoids caught in the field. In some cases, LbTV was found in coinfection with LbFV, but did not affect the behaviour of the wasp. Instead we found that the presence of LbTV correlates with an increase in the number of offspring, mostly due to increased survival of parasitoid larvae. LbTV is vertically transmitted mostly through the maternal lineage even if frequent paternal transmission also occurs. Unlike LbFV, LbTV is not horizontally transmitted. Its genome encodes a putative RNA-dependent RNA polymerase (RdRp) showing similarities with RdRps of Totiviridae. These results underline the high incidence and diversity of inherited viruses in parasitoids as well as their potential impact on the phenotype of their hosts.
authors.affiliation: Université Lyon 1, CNRS, UMR 5558, Laboratoire de Biométrie et Biologie Evolutive, Lyon, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Martinez
authors.affiliation: Université Lyon 1, CNRS, UMR 5558, Laboratoire de Biométrie et Biologie Evolutive, Lyon, France.
authors.forename: David
authors.initials: D
authors.lastname: Lepetit
authors.affiliation: Unité BiVi (Biologie Intégrative et Virologie des Insectes), Université Montpellier II-INRA 1231, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Ravallec
authors.affiliation: Université Lyon 1, CNRS, UMR 5558, Laboratoire de Biométrie et Biologie Evolutive, Lyon, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Fleury
authors.affiliation: Université Lyon 1, CNRS, UMR 5558, Laboratoire de Biométrie et Biologie Evolutive, Lyon, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Varaldi
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D016000:Cluster Analysis; D005260:Female; D018445:Infectious Disease Transmission, Vertical; D007304:Insect Viruses / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D015995:Prevalence; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D016019:Survival Analysis; D019196:Totiviridae / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D014863:Wasps / Q000502:physiology / Q000821:virology*; D014918:Wills
chemical_list: D012367:RNA, Viral