VIRION
Non-enveloped capsids with T=1 icosahedral symmetry. Capsids are often bacilliform with a diameter of 18nm, and length varies from 30nm to 62 nm depending on the number of supplemental capsid discs.
GENOME
Segmented, linear, ssRNA(+) genome. The three segments are 0.9kb, 1.0kb and 2.8kb in size respectively.
GENE EXPRESSION
Genomic RNAs serve as messenger RNAs.
REPLICATION
CYTOPLASMIC
- Virus penetrates into the host cell.
- Uncoating, and release of the viral genomic RNA into the cytoplasm.
- The viral RNAs are translated to produce the three viral proteins.
- Replication takes place in cytoplasmic viral factories. A dsRNA genome is synthesized from the genomic ssRNA(+).
- The dsRNA genome is transcribed/replicated thereby providing viral mRNAs/new ssRNA(+) genomes.
- Virus assembly, each segment is encapsidated possibly individually.
- Viral movement protein probably mediates virion cell-to-cell transfer.