title: Multiple occurrences of giant virus core genes acquired by eukaryotic genomes: the visible part of the iceberg?
abstract: Giant Viruses are a widespread group of viruses, characterized by huge genomes composed of a small subset of ancestral, vertically inherited core genes along with a large body of highly variable genes. In this study, I report the acquisition of 23 core ancestral Giant Virus genes by diverse eukaryotic species including various protists, a moss and a cnidarian. The viral genes are inserted in large scaffolds or chromosomes with intron-rich, eukaryotic-like genomic contexts, refuting the possibility of DNA contaminations. Some of these genes are expressed and in the cryptophyte alga Guillardia theta, a possible non-homologous displacement of the eukaryotic DNA primase by a viral D5 helicase/primase is documented. As core Giant Virus genes represent only a tiny fraction of the total genomic repertoire of these viruses, these results suggest that Giant Viruses represent an underestimated source of new genes and functions for their hosts.
authors.affiliation: Laboratoire Evolution, Genomes, Spéciation (LEGS), CNRS UPR9034, Université Paris-Sud. Avenue de la Terrasse, 91190 Gif Sur Yvette, France. Electronic address: jonathan.filee@legs.cnrs-gif.fr.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Filée
mesh_terms: D002875:Chromosomes / Q000235:genetics; D044785:Cryptophyta / Q000235:genetics / Q000821:virology; D019915:DNA Primase / Q000235:genetics; D004267:DNA Viruses / Q000145:classification / Q000235:genetics*; D004279:DNA, Viral / Q000235:genetics; D056890:Eukaryota / Q000235:genetics* / Q000821:virology; D019143:Evolution, Molecular; D022761:Gene Transfer, Horizontal; D016678:Genome / Q000235:genetics*; D016679:Genome, Viral / Q000235:genetics*; D023281:Genomics; D054884:Host-Pathogen Interactions; D010802:Phylogeny; D014764:Viral Proteins / Q000235:genetics*
chemical_list: D004279:DNA, Viral; D014764:Viral Proteins; D019915:DNA Primase
keywords: Displacement; Genome evolution; Giant virus; Lateral gene transfer; Non homologous gene