Notes on Family: Partitiviridae

icosahedra
icosahedra

Contents

General Description

This family is characterised by its icosahedral particles and its double stranded RNA genome with two components. The viruses are mostly associated with latent infections of fungal or plant hosts. The family is named from the Latin partitus, meaning "divided". Viruses of fungi previously in this family but with four genomic components are now placed in the family Chrysoviridae.

Morphology

Virions isometric, icosahedral, not enveloped, 30-40 nm in diameter and of two types.

Genomen

Linear, double stranded RNA of two segments. The segments are of roughly similar size in the range 1.4-3.0kb each. Smaller defective or satellite RNAs may also be present. The segments are monocistronic: one encodes the coat protein and another an RNA polymerase.

Genera in the Family

  • Alphacryptovirus (infecting plants, virions 30 nm diameter)
  • Betacryptovirus (infecting plants, virions 38 nm diameter)
  • Cryspovirus (infecting protozoa, virions 30 nm diameter, small coat protein and phylogenetically distinct RdRp)
  • Partitivirus (usually infecting fungi, virions 30-35nm diameter)