This article reports the changes to virus taxonomy approved and ratified by the International Committee on Taxonomy of Viruses (ICTV) in March 2021. The entire ICTV was invited to vote on 290 ...taxonomic proposals approved by the ICTV Executive Committee at its meeting in October 2020, as well as on the proposed revision of the International Code of Virus Classification and Nomenclature (ICVCN). All proposals and the revision were ratified by an absolute majority of the ICTV members. Of note, ICTV mandated a uniform rule for virus species naming, which will follow the binomial 'genus-species' format with or without Latinized species epithets. The Study Groups are requested to convert all previously established species names to the new format. ICTV has also abolished the notion of a type species, i.e., a species chosen to serve as a name-bearing type of a virus genus. The remit of ICTV has been clarified through an official definition of ‘virus’ and several other types of mobile genetic elements. The ICVCN and ICTV Statutes have been amended to reflect these changes.
ICTV Virus Taxonomy Profile: Partitiviridae Vainio, Eeva J; Chiba, Sotaro; Ghabrial, Said A ...
Journal of general virology,
01/2018, Letnik:
99, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The Partitiviridae is a family of small, isometric, non-enveloped viruses with bisegmented double-stranded (ds) RNA genomes of 3-4.8 kbp. The two genome segments are individually encapsidated. The ...family has five genera, with characteristic hosts for members of each genus: either plants or fungi for genera Alphapartitivirus and Betapartitivirus, fungi for genus Gammapartitivirus, plants for genus Deltapartitivirus and protozoa for genus Cryspovirus. Partitiviruses are transmitted intracellularly via seeds (plants), oocysts (protozoa) or hyphal anastomosis, cell division and sporogenesis (fungi); there are no known natural vectors. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of the Partitiviridae, which is available at www.ictv.global/report/partitiviridae.
The family Endornaviridae includes viruses with linear, single-stranded, positive-sense RNA genomes that range from 9.7 to 17.6 kb and have been reported infecting plants, fungi and oomycetes. The ...family consists of two genera, Alphaendornavirus and Betaendornavirus, into which viruses are classified based on their genome size, host and presence of unique domains. Alphaendornavirus includes species whose members infect plants, fungi and oomycetes, while the genus Betaendornavirus includes species whose members infect ascomycete fungi. This is a summary of the ICTV Report on the family Endornaviridae, which is available at www.ictv.global/report/endornaviridae.
Viruses in the family
have a mono-, bi- or tripartite positive-sense RNA genome of 13-19 kb, and non-enveloped, filamentous particles 650-2200 nm long and 12 nm in diameter. They infect plants, ...mainly dicots, many of which are fruit crops. This is a summary of the ICTV Report on the family
, which is available at ictv.global/report/closteroviridae.
The Executive Committee of the International Committee on Taxonomy of Viruses (ICTV) recognizes the need for a standardized nomenclature for virus species. This article sets out the case for ...establishing a binomial nomenclature and presents the advantages and disadvantages of different naming formats. The Executive Committee understands that adopting a binomial system would have major practical consequences, and invites comments from the virology community before making any decisions to change the existing nomenclature. The Executive Committee will take account of these comments in deciding whether to approve a standardized binomial system at its next meeting in October 2020. Note that this system would relate only to the formal names of virus species and not to the names of viruses.
This article lists the changes to virus taxonomy approved and ratified by the International Committee on Taxonomy of Viruses (ICTV) in April 2016.
Changes to virus taxonomy (the Universal Scheme of ...Virus Classification of the International Committee on Taxonomy of Viruses ICTV) now take place annually and are the result of a multi-stage process. In accordance with the ICTV Statutes (
http://www.ictvonline.org/statutes.asp
), proposals submitted to the ICTV Executive Committee (EC) undergo a review process that involves input from the ICTV Study Groups (SGs) and Subcommittees (SCs), other interested virologists, and the EC. After final approval by the EC, proposals are then presented for ratification to the full ICTV membership by publication on an ICTV web site (
http://www.ictvonline.org/
) followed by an electronic vote. The latest set of proposals approved by the EC was made available on the ICTV website by January 2016 (
https://talk.ictvonline.org/files/proposals/
). A list of these proposals was then emailed on 28 March 2016 to the 148 members of ICTV, namely the EC Members, Life Members, ICTV Subcommittee Members (including the SG chairs) and ICTV National Representatives. Members were then requested to vote on whether to ratify the taxonomic proposals (voting closed on 29 April 2016).
Analyses of Illumina-based high-throughput sequencing data generated during characterization of the cotton leafroll dwarf virus population in Mississippi (2020–2022) consistently yielded contigs ...varying in size (most frequently from 4 to 7 kb) with identical nucleotide content and sharing similarities with reverse transcriptases (RTases) encoded by extant plant pararetroviruses (family Caulimoviridiae). Initial data prompted an in-depth study involving molecular and bioinformatic approaches to characterize the nature and origins of these caulimovirid-like sequences. As a result, here, we report on endogenous viral elements (EVEs) related to extant members of the family Caulimoviridae, integrated into a genome of upland cotton (Gossypium hirsutum), for which we propose the provisional name “endogenous cotton pararetroviral elements” (eCPRVE). Our investigations pinpointed a ~15 kbp-long locus on the A04 chromosome consisting of head-to-head orientated tandem copies located on positive- and negative-sense DNA strands (eCPRVE+ and eCPRVE-). Sequences of the eCPRVE+ comprised nearly complete and slightly decayed genome information, including ORFs coding for the viral movement protein (MP), coat protein (CP), RTase, and transactivator/viroplasm protein (TA). Phylogenetic analyses of major viral proteins suggest that the eCPRVE+ may have been initially derived from a genome of a cognate virus belonging to a putative new genus within the family. Unexpectedly, an identical 15 kb-long locus composed of two eCPRVE copies was also detected in a newly recognized species G. ekmanianum, shedding some light on the relatively recent evolution within the cotton family.
A universal taxonomy of viruses is essential for a comprehensive view of the virus world and for communicating the complicated evolutionary relationships among viruses. However, there are major ...differences in the conceptualisation and approaches to virus classification and nomenclature among virologists, clinicians, agronomists, and other interested parties. Here, we provide recommendations to guide the construction of a coherent and comprehensive virus taxonomy, based on expert scientific consensus. Firstly, assignments of viruses should be congruent with the best attainable reconstruction of their evolutionary histories, i.e., taxa should be monophyletic. This fundamental principle for classification of viruses is currently included in the International Committee on Taxonomy of Viruses (ICTV) code only for the rank of species. Secondly, phenotypic and ecological properties of viruses may inform, but not override, evolutionary relatedness in the placement of ranks. Thirdly, alternative classifications that consider phenotypic attributes, such as being vector-borne (e.g., "arboviruses"), infecting a certain type of host (e.g., "mycoviruses," "bacteriophages") or displaying specific pathogenicity (e.g., "human immunodeficiency viruses"), may serve important clinical and regulatory purposes but often create polyphyletic categories that do not reflect evolutionary relationships. Nevertheless, such classifications ought to be maintained if they serve the needs of specific communities or play a practical clinical or regulatory role. However, they should not be considered or called taxonomies. Finally, while an evolution-based framework enables viruses discovered by metagenomics to be incorporated into the ICTV taxonomy, there are essential requirements for quality control of the sequence data used for these assignments. Combined, these four principles will enable future development and expansion of virus taxonomy as the true evolutionary diversity of viruses becomes apparent.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This article reports the changes to virus taxonomy approved and ratified by the International Committee on Taxonomy of Viruses (ICTV) in October 2018. Of note, the ICTV has approved, by an absolute ...majority, the creation of additional taxonomical ranks above those recognized previously. A total of 15 ranks (realm, subrealm, kingdom, subkingdom, phylum, subphylum, class, subclass, order, suborder, family, subfamily, genus, subgenus, and species) are now available to encompass the entire spectrum of virus diversity. Classification at ranks above genus is not obligatory but can be used by the authors of new taxonomic proposals when scientific justification is provided.
PDF
