Family: Polyomaviridae

Genus: Betapolyomavirus

Distinguishing features

The best-studied human polyomaviruses, BK polyomavirus (BKPyV) and JC polyomavirus (JCPyV) belong to this genus and are associated with nephropathy and progressive multifocal leukoencephalopathy, respectively. 

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.)