Non-enveloped, bacilliform, about 50 nm in length and 30 nm in width, resembling those of cileviruses.
Segmented, tripartite, linear, ssRNA(+) genome. The three segments are about 8.4, 3.2 and 3.1 kb in size. The genomic RNA is capped, and polyadenylated.
Genomic RNAs serve as messenger RNAs. RNA1 contains 1 ORF encoding the replicase. RNA2 contains 4 ORFs, and may encode a movement proteins. RNA3 contains 3 ORFs.
- Virus penetrates into the host cell.
- Uncoating, and release of the viral genomic RNA into the cytoplasm.
- The viral RNA is translated to produce the two proteins necessary for RNA synthesis (replication and transcription).
- 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.
- Expression of the subgenomic RNAs (sgRNAs).
- Each segment is encapsidated.
- Viral movement proteins probably mediate virion cell-to-cell transfer.