Family: Polyomaviridae

Genus: Alphapolyomavirus

Distinguishing features

Members infect humans and other mammals. Merkel cell polyomavirus (MCPyV) and raccoon polyomavirus RacPyV) are so far the only members known to cause cancer in their natural host. 

Virion

See discussion under family description. 

Genome organization and replication

See discussion under family description. 

Biology

See discussion under family description. 

Species demarcation criteria

1. Sufficient information on the natural host
2. Observed genetic distance from a member of the most closely related species is >15% nucleotide difference for the LTAg coding sequence
3. When two polyomaviruses exhibit <15% observed genetic distance (as defined above), biological properties may be of additional critical importance (e.g. host specificity, disease association, tissue tropism, etc.)