VIRION
Virions consist of four to five non enveloped nucleocapsids, about 3-10 nm in diameter
GENOME
The genome is segmented and consists of four or five segments of linear negative-sense and ambisense single-stranded RNA. The complete genome is around 16 kb.
GENE EXPRESSION
The viral RNA dependent RNA polymerase (L) binds to a promoter on each encapsidated segment, and transcribes the mRNAs. These are capped by L protein during synthesis using cap snatching . Segments 2, 3 and 4 are ambisens.
REPLICATION
CYTOPLASMIC
- Virus enters into host cells by mechanical injection or through plasmodesmatas
- Transcription, viral mRNAs are capped in the cytoplasm.
- Replication presumably starts when enough nucleoprotein is present to encapsidate neo-synthetized antigenomes and genomes.
- The ribonucleocapsids migrates to new cells using movement proteins.