A taxonomy update for the family Polyomaviridae

Area of Science:

• Virology
• Taxonomy
• Genomics

Background:

• Numerous distinct polyomaviruses infecting diverse vertebrate hosts have been identified, with complete genome sequences frequently determined.
• The rapid discovery of new polyomaviruses necessitated an updated classification system to manage increasing viral diversity.

Discussion:

• The International Committee on Taxonomy of Viruses (ICTV) Polyomaviridae Study Group developed a host- and sequence-based rationale for revising the Polyomaviridae family taxonomy.
• Taxonomical revisions were accepted by the ICTV Executive Committee in December 2015, establishing new criteria for defining and creating polyomavirus species.
• New species definitions are based on sequence divergence in large T antigen coding regions, ensuring a more precise classification.

Key Insights:

• Four genera—Alphapolyomavirus, Betapolyomavirus, Gammapolyomavirus, and Deltapolyomavirus—were delineated, encompassing a total of 73 species.
• A systematic approach to species naming was adopted, typically using the host's binomial name followed by 'polyomavirus' and a discovery order number.
• This updated taxonomy provides a stable framework for classifying the expanding diversity of polyomaviruses.

Outlook:

• The revised taxonomy is expected to facilitate the integration of future polyomavirus discoveries.
• Standardized nomenclature will aid researchers in communicating and organizing information about these viruses.
• This classification update supports ongoing research into polyomavirus evolution and host interactions.