Genomic architecture of endogenous ichnoviruses reveals distinct evolutionary pathways leading to virus domestication in parasitic wasps

BMC Biology

Gabor Gyapay¹  Anne-Nathalie Volkoff²  Marc Ravallec²  Véronique Jouan²  Xin Zhou³  Shanlin Liu³  Rebecca B. Dikow⁴  Bernardo F. Santos⁴  Seán G. Brady⁴  Bruce A. Webb⁵  Anthony Bretaudeau⁶  Stéphanie Robin⁶  Fabrice Legeai⁶  Denis Tagu⁶  Frédéric Baudat⁷  Jean-Michel Drezen⁸  Claire Lemaitre⁹ 

[1] Commissariat à l’Energie Atomique (CEA), Institut de Génomique (IG), Genoscope, 2 rue Gaston Crémieux;DGIMI, INRAE, University of Montpellier;Department of Entomology, China Agricultural University;Department of Entomology, National Museum of Natural History, Smithsonian Institution;Department of Entomology, University of Kentucky;IGEPP, Agrocampus Ouest, INRAE, Université de Rennes 1;Institut de Génétique Humaine, CNRS, University of Montpellier;Institut de Recherche sur la Biologie de l’Insecte, UMR 7261, CNRS - Université de Tours, UFR des Sciences et Techniques;Université Rennes 1, INRIA, CNRS, IRISA;

关键词: Endogenous virus architecture;    Polydnavirus;    Parasitoid wasp;    Koinobiont;    Campopleginae;    IVSPERs;   

DOI  :  10.1186/s12915-020-00822-3

来源: DOAJ

【 摘 要 】

Abstract Background Polydnaviruses (PDVs) are mutualistic endogenous viruses inoculated by some lineages of parasitoid wasps into their hosts, where they facilitate successful wasp development. PDVs include the ichnoviruses and bracoviruses that originate from independent viral acquisitions in ichneumonid and braconid wasps respectively. PDV genomes are fully incorporated into the wasp genomes and consist of (1) genes involved in viral particle production, which derive from the viral ancestor and are not encapsidated, and (2) proviral segments harboring virulence genes, which are packaged into the viral particle. To help elucidating the mechanisms that have facilitated viral domestication in ichneumonid wasps, we analyzed the structure of the viral insertions by sequencing the whole genome of two ichnovirus-carrying wasp species, Hyposoter didymator and Campoletis sonorensis. Results Assemblies with long scaffold sizes allowed us to unravel the organization of the endogenous ichnovirus and revealed considerable dispersion of the viral loci within the wasp genomes. Proviral segments contained species-specific sets of genes and occupied distinct genomic locations in the two ichneumonid wasps. In contrast, viral machinery genes were organized in clusters showing highly conserved gene content and order, with some loci located in collinear wasp genomic regions. This genomic architecture clearly differs from the organization of PDVs in braconid wasps, in which proviral segments are clustered and viral machinery elements are more dispersed. Conclusions The contrasting structures of the two types of ichnovirus genomic elements are consistent with their different functions: proviral segments are vehicles for virulence proteins expected to adapt according to different host defense systems, whereas the genes involved in virus particle production in the wasp are likely more stable and may reflect ancestral viral architecture. The distinct genomic architectures seen in ichnoviruses versus bracoviruses reveal different evolutionary trajectories that have led to virus domestication in the two wasp lineages.

【 授权许可】

Unknown