title: Faustoviruses: Comparative Genomics of New Megavirales Family Members.
abstract: An emerging interest for the giant virus discovery process, genome sequencing and analysis has allowed an expansion of the number of known Megavirales members. Using the protist Vermamoeba sp. as cell support, a new giant virus named Faustovirus has been isolated. In this study, we describe the genome sequences of nine Faustoviruses and build a genomic comparison in order to have a comprehensive overview of genomic composition and diversity among this new virus family. The average sequence length of these viruses is 467,592.44 bp (ranging from 455,803 to 491,024 bp), making them the fourth largest Megavirales genome after Mimiviruses, Pandoraviruses, and Pithovirus sibericum. Faustovirus genomes displayed an average G+C content of 37.14 % (ranging from 36.22 to 39.59%) which is close to the G+C content range of the Asfarviridae genomes (38%). The proportion of best matches and the phylogenetic analysis suggest a shared origin with Asfarviridae without belonging to the same family. The core-gene-based phylogeny of Faustoviruses study has identified four lineages. These results were confirmed by the analysis of amino acids and COGs category distribution. The diversity of the gene composition of these lineages is mainly explained by gene deletion or acquisition and some exceptions for gene duplications. The high proportion of best matches from Bacteria and Phycodnaviridae on the pan-genome and unique genes may be explained by an interaction occurring after the separation of the lineages. The Faustovirus core-genome appears to consolidate the surrounding of 207 genes whereas the pan-genome is described as an open pan-genome, its enrichment via the discovery of new Faustoviruses is required to better seize all the genomic diversity of this family.
authors.affiliation: UM63 CNRS 7278 IRD 198 INSERM U1095, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, Facultés de Médecine et de Pharmacie, Aix-Marseille University Marseille, France.
authors.forename: Samia
authors.initials: S
authors.lastname: Benamar
authors.affiliation: UM63 CNRS 7278 IRD 198 INSERM U1095, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, Facultés de Médecine et de Pharmacie, Aix-Marseille University Marseille, France.
authors.forename: Dorine G I
authors.initials: DG
authors.lastname: Reteno
authors.affiliation: Pôle des Maladies Infectieuses et Tropicales Clinique et Biologique, Fédération de Bactériologie-Hygiène-Virologie, Institut Hospitalo-Universitaire Méditerranée Infection, Centre Hospitalo-Universitaire Timone, Assistance Publique - Hôpitaux de Marseille Marseille, France.
authors.forename: Victor
authors.initials: V
authors.lastname: Bandaly
authors.affiliation: UM63 CNRS 7278 IRD 198 INSERM U1095, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, Facultés de Médecine et de Pharmacie, Aix-Marseille University Marseille, France.
authors.forename: Noémie
authors.initials: N
authors.lastname: Labas
authors.affiliation: UM63 CNRS 7278 IRD 198 INSERM U1095, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, Facultés de Médecine et de Pharmacie, Aix-Marseille UniversityMarseille, France; Pôle des Maladies Infectieuses et Tropicales Clinique et Biologique, Fédération de Bactériologie-Hygiène-Virologie, Institut Hospitalo-Universitaire Méditerranée Infection, Centre Hospitalo-Universitaire Timone, Assistance Publique - Hôpitaux de MarseilleMarseille, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
authors.affiliation: UM63 CNRS 7278 IRD 198 INSERM U1095, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, Facultés de Médecine et de Pharmacie, Aix-Marseille UniversityMarseille, France; Pôle des Maladies Infectieuses et Tropicales Clinique et Biologique, Fédération de Bactériologie-Hygiène-Virologie, Institut Hospitalo-Universitaire Méditerranée Infection, Centre Hospitalo-Universitaire Timone, Assistance Publique - Hôpitaux de MarseilleMarseille, France.
authors.forename: Bernard
authors.initials: B
authors.lastname: La Scola
keywords: Faustovirus; genomic comparison; giant viruses; pan-genome; phylogenetic