This form should be used for all taxonomic proposals. Please complete all those modules that are applicable (and then delete the unwanted sections). For guidance, see the notes written in blue and the separate document “Help with completing a taxonomic proposal” Please try to keep related proposals within a single document; you can copy the modules to create more than one genus within a new family, for example. MODULE 1: TITLE, AUTHORS, etc (to be completed by ICTV Code assigned: 2015.001a-kF officers) Short title: A new family and two new genera for classification of virophages two new species (e.g. 6 new species in the genus Zetavirus) Modules attached 1 2 3 4 5 (modules 1 and 10 are required) 6 7 8 9 10 Author(s): Matthias Fischer – Max Planck Institute for Medical Research, Germany Mart Krupovic – Institut Pasteur, France Jens H. Kuhn – NIH/NIAID/IRF-Frederick, Maryland, USA Bernard La Scola – Aix Marseille Université, France Didier Raoult – Aix Marseille Université, France Corresponding author with e-mail address: Matthias Fischer, [email protected] Mart Krupovic, [email protected] List the ICTV study group(s) that have seen this proposal: A list of study groups and contacts is provided at http://www.ictvonline.org/subcommittees.asp . If in doubt, contact the appropriate subcommittee chair (fungal, invertebrate, plant, prokaryote or vertebrate viruses) ICTV Study Group comments (if any) and response of the proposer: Date first submitted to ICTV: June 11, 2015 Date of this revision (if different to above): ICTV-EC comments and response of the proposer: Fungal and Protist Viruses Subcommittee Chair: Proposal approved for submission. Page 1 of 14 MODULE 2a: NEW SPECIES creating and naming one or more new species. If more than one, they should be a group of related species belonging to the same genus. All new species must be placed in a higher taxon. This is usually a genus although it is also permissible for species to be “unassigned” within a subfamily or family. Wherever possible, provide sequence accession number(s) for one isolate of each new species proposed. Code 2015.001aF (assigned by ICTV officers) To create 2 new species within: Fill in all that apply. Genus: Sputnikvirus (new) If the higher taxon has yet to be created (in a later module, below) write Subfamily: “(new)” after its proposed name. Family: Lavidaviridae (new) If no genus is specified, enter Order: “unassigned” in the genus box. Name of new species: Representative isolate: (only 1 GenBank sequence per species please) accession number(s) Mimivirus-dependent virus Sputnik virus 1 EU606015 Sputnik Mimivirus-dependent virus Zamilon virus HG531932 Zamilon Reasons to justify the creation and assignment of the new species: Explain how the proposed species differ(s) from all existing species. o If species demarcation criteria (see module 3) have previously been defined for the genus, explain how the new species meet these criteria. o If criteria for demarcating species need to be defined (because there will now be more than one species in the genus), please state the proposed criteria. Further material in support of this proposal may be presented in the Appendix, Module 9 Both virus species represent satellite-like viruses of protists, also known as virophages, which depend for multiplication on members of the genus Mimivirus within the family Mimiviridae. Sputnik and Zamilon are able to replicate in Acanthamoeba polyphaga cells that are co-infected with Acanthamoeba polyphaga mimivirus (APMV) or Mont1 mimivirus, respectively [1, 2]. The latter virus is more closely related to “Megavirus chilensis” [3] than to APMV [4]. Both Sputnik and Zamilon have similarly-sized (17,276-18,342 base pairs), circular double-stranded DNA genomes that code for 20-21 proteins (Module 10; Figure 1) [1, 2, 5, 6]. The virions are icosahedral with a diameter of 60-75 nm, and are composed of at least two different proteins with jelly-roll folds, the minor and the major capsid protein (Module 10; Figure 2a) [7, 8]. The capsid proteins of viruses in the proposed genus are homologous and the major capsid protein can be used as a phylogenetic marker to demonstrate membership in the proposed genus (Module 10; Figure 3). In addition to the two capsid protein genes, both species encode a FtsK-HerA family DNA- packaging ATPase, a cysteine protease, a primase-superfamily 3 helicase, a lambda-type integrase, a transposase, a Zinc-ribbon domain protein, a collagen-like protein, and six proteins of unknown function [1, 2]. Page 2 of 14 MODULE 2b: NEW SPECIES creating and naming one or more new species. If more than one, they should be a group of related species belonging to the same genus. All new species must be placed in a higher taxon. This is usually a genus although it is also permissible for species to be “unassigned” within a subfamily or family. Wherever possible, provide sequence accession number(s) for one isolate of each new species proposed. Code 2015.001bF (assigned by ICTV officers) To create 1 new species within: Fill in all that apply. Genus: Mavirus (new) If the higher taxon has yet to be created (in a later module, below) write Subfamily: “(new)” after its proposed name. Family: Lavidaviridae (new) If no genus is specified, enter Order: “unassigned” in the genus box. Name of new species: Representative isolate: (only 1 GenBank sequence per species please) accession number(s) Cafeteriavirus-dependent Maverick-related virus HQ712116 mavirus (Mavirus), strain Spezl Reasons to justify the creation and assignment of the new species: Explain how the proposed species differ(s) from all existing species. o If species demarcation criteria (see module 3) have previously been defined for the genus, explain how the new species meet these criteria. o If criteria for demarcating species need to be defined (because there will now be more than one species in the genus), please state the proposed criteria. Further material in support of this proposal may be presented in the Appendix, Module 9 Mavirus replicates in the marine heterotrophic nanoflagellate Cafeteria roenbergensis in the presence of Cafeteria roenbergensis virus (CroV) [9, 10]. The circular, double-stranded DNA genome consists of 19,063 bp and encodes 20 proteins. The virions are icosahedral with a diameter of ~75 nm, and are composed of at least two different proteins with jelly-roll folds, the minor and the major capsid protein (Module 10; Figure 2b). The capsid proteins of viruses in the proposed genus are homologous and the major capsid protein can be used as a phylogenetic marker to demonstrate membership in the proposed genus (Module 10; Figure 3). In addition to the two capsid protein genes, Mavirus encodes a FtsK-HerA family DNA- packaging ATPase, a cysteine protease, a superfamily 3 helicase, a retroviral-type integrase, a lipase, and a FNIP repeat-containing protein [9]. Mavirus shares many features with the large, virus-like transposons of the Maverick/Polinton superfamily which are widespread in eukaryotes [11, 12]. Both types of elements encode 7 homologous proteins involved in virion morphogenesis (minor and major capsid proteins, FtsK-HerA-type genome packaging ATPase and cysteine protease homologous to adenoviral maturation proteases), genome replication (protein-primed family B DNA polymerase and superfamily 3 helicase) and integration (retrovirus-like integrase which belongs to a broad superfamily of DDE transposases) [9, 13]. Furthermore, the Mavirus genome contains long inverted repeats that resemble those found at the termini of Maverick/Polinton transposons. Page 3 of 14 MODULE 3a: NEW GENUS creating a new genus Ideally, a genus should be placed within a higher taxon. Code 2015.001cF (assigned by ICTV officers) To create a new genus within: Fill in all that apply. Subfamily: If the higher taxon has yet to be created (in a later module, below) write “(new)” Family: Lavidaviridae (new) after its proposed name. Order: If no family is specified, enter “unassigned” in the family box naming a new genus Code 2015.001dF (assigned by ICTV officers) To name the new genus: Sputnikvirus Assigning the type species and other species to a new genus Code 2015.001eF (assigned by ICTV officers) To designate the following as the type species of the new genus Every genus must have a type species. This should Mimivirus-dependent virus Sputnik be a well characterized species although not necessarily the first to be discovered The new genus will also contain any other new species created and assigned to it (Module 2) and any that are being moved from elsewhere (Module 7b). Please enter here the TOTAL number of species (including the type species) that the genus will contain: 2 Reasons to justify the creation of a new genus: Additional material in support of this proposal may be presented in the Appendix, Module 9 Viruses in this genus depend on members of the genus Mimivirus within the family Mimiviridae for multiplication and are able to replicate in Acanthamoeba polyphaga cells that are co-infected with their respective associated giant virus. All viruses in this genus contain similarly-sized (17,276-18,342 base pairs), circular double-stranded DNA genomes that code for 20-21 proteins. (Module 10; Figure 1) [1, 2, 5, 6]. The virions are icosahedral with a diameter of 60-75 nm, and are composed of at least two different proteins with jelly-roll folds, the minor and the major capsid protein (Module 10; Figure 2a) [7, 8]. In addition to the two capsid protein genes, both species encode a FtsK-HerA family DNA- packaging ATPase, a cysteine protease, a primase-superfamily 3 helicase, a lambda-type integrase, a transposase, a Zinc-ribbon domain protein, a collagen-like protein, and six proteins of unknown function [1, 2].