title: Chimeric viruses blur the borders between the major groups of eukaryotic single-stranded DNA viruses.
abstract: Metagenomic studies have uncovered an astonishing diversity of ssDNA viruses encoding replication proteins (Reps) related to those of eukaryotic Circoviridae, Geminiviridae or Nanoviridae; however, exact evolutionary relationships among these viruses remain obscure. Recently, a unique chimeric virus (CHIV) genome, which has apparently emerged via recombination between ssRNA and ssDNA viruses, has been discovered. Here we report on the assembly of 13 new CHIV genomes recovered from various environments. Our results indicate a single event of capsid protein (CP) gene capture from an RNA virus in the history of this virus group. The domestication of the CP gene was followed by an unprecedented recurrent replacement of the Rep genes in CHIVs with distant counterparts from diverse ssDNA viruses. We suggest that parasitic and symbiotic interactions between unicellular eukaryotes were central for the emergence of CHIVs and that such turbulent evolution was primarily dictated by incongruence between the CP and Rep proteins.
authors.affiliation: 1] Laboratoire 'Microorganismes: Génome et Environnement', Clermont Université, Université Blaise Pascal, Clermont-Ferrand 63000, France [2] CNRS UMR 6023, LMGE, Aubière 63171, France.
authors.forename: Simon
authors.initials: S
authors.lastname: Roux
authors.forename: François
authors.initials: F
authors.lastname: Enault
authors.forename: Gisèle
authors.initials: G
authors.lastname: Bronner
authors.forename: Daniel
authors.initials: D
authors.lastname: Vaulot
authors.forename: Patrick
authors.initials: P
authors.lastname: Forterre
authors.forename: Mart
authors.initials: M
authors.lastname: Krupovic
mesh_terms: D036022:Capsid Proteins / Q000235:genetics*; D004267:DNA Viruses / Q000145:classification* / Q000235:genetics; D004277:DNA, Single-Stranded / Q000235:genetics; D004279:DNA, Viral / Q000235:genetics; D019143:Evolution, Molecular; D015723:Gene Library; D016679:Genome, Viral; D056186:Metagenomics; D010802:Phylogeny; D012328:RNA Viruses / Q000145:classification* / Q000235:genetics; D011995:Recombination, Genetic
chemical_list: D036022:Capsid Proteins; D004277:DNA, Single-Stranded; D004279:DNA, Viral