Revisiting the Taxonomy of the Family Circoviridae: Establishment of the Genus Cyclovirus and Removal of the Genus Gyrovirus

Mya Breitbart, Balázs Harrach, Joaquim Segalés, Eric Delwart, Philippe Biagini, Arvind Varsani

Research output: Contribution to journalArticlepeer-review

Abstract

<p> <p id="x-x-Par1"> The family <em> Circoviridae </em> contains viruses with covalently closed, circular, single-stranded DNA (ssDNA) genomes, including the smallest known autonomously replicating, capsid-encoding animal pathogens. Members of this family are known to cause fatal diseases in birds and pigs and have been historically classified in one of two genera: <em> Circovirus </em> , which contains avian and porcine pathogens, and <em> Gyrovirus </em> , which includes a single species ( <em> Chicken anemia virus </em> ). However, over the course of the past six years, viral metagenomic approaches as well as degenerate PCR detection in unconventional hosts and environmental samples have elucidated a broader host range, including fish, a diversity of mammals, and invertebrates, for members of the family <em> Circoviridae </em> . Notably, these methods have uncovered a distinct group of viruses that are closely related to members of the genus <em> Circovirus </em> and comprise a new genus, <em> Cyclovirus </em> . The discovery of new viruses and a re-evaluation of genomic features that characterize members of the <em> Circoviridae </em> prompted a revision of the classification criteria used for this family of animal viruses. Here we provide details on an updated <em> Circoviridae </em> taxonomy ratified by the International Committee on the Taxonomy of Viruses in 2016, which establishes the genus <em> Cyclovirus </em> and reassigns the genus <em> Gyrovirus </em> to the family <em> Anelloviridae, </em> a separate lineage of animal viruses that also contains circular ssDNA genomes. In addition, we provide a new species demarcation threshold of 80% genome-wide pairwise identity for members of the family <em> Circoviridae </em> , based on pairwise identity distribution analysis, and list guidelines to distinguish between members of this family and other eukaryotic viruses with circular, ssDNA genomes. </p></p>
Original languageAmerican English
JournalArchives of Virology
Volume162
DOIs
StatePublished - Jan 1 2017

Keywords

  • Genomic Feature
  • Animal Virus
  • Chicken Anemia Virus
  • Pairwise Identity
  • ssDNA Virus

Disciplines

  • Life Sciences

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