Notes on Family: Filoviridae

eveloped filaments or bacilliform
eveloped filaments or bacilliform
eveloped filaments or bacilliform

Contents

General Description

This family is characterised by its pleomorphic but usually filamentous or bacilliform, enveloped, particles which contain a monopartite negative sense ssRNA genome of about 19kb. It is classified in the order Mononegavirales with three other families of enveloped viruses with monopartite negative sense genomes, i.e. the Bornaviridae and Paramyxoviridae (both with spherical particles) and Rhabdoviridae (particles bullet-shaped and genome up to about 15 kb).

Morphology

Virions pleomorphic but usually filamentous or bacilliform, enveloped, about 80 nm in diameter and up to about 970nm long (although they may appear longer because of aggregation), with small (10 nm) projections.

Genomen

Monopartite single-stranded negative sense RNA of about 19 kb. There is no genome-linked protein (VPg) at the 5'-terminus nor a 3'-polyA tail. There are 7 major ORFs with the RNA polymerase at the 5'-end of the genome and the capsid nucleoprotein at the 3'-end.

Genera in the Family

  • Ebolavirus: virions 970nm long; several gene overlaps
  • Marburgvirus: virions 790nm long; only one gene overlap