Molecular biology
VIRION
Non-enveloped icosahedric capsid with a T=1 symmetry. about 35-40 nm in diameter. The four genomic segments are encapsidated separately.
GENOME
Segmented dsRNA linear genome: 4 segments encoding for 4 proteins.
GENE EXPRESSION
Each genomic segment encodes for a single protein.
REPLICATION
CYTOPLASMIC
- Virus penetrates into the cytoplasm.
- Transcription of the dsRNA genome by viral polymerase occurs inside the virion, so that dsRNA is never exposed to the cytoplasm? This plus-strand transcript is used as template for translation.
- (+)RNAs are encapsidated in virion particle, inside which they are transcribed to give RNA (-) molecules with which they become base-paired to produce dsRNA genomes.
- Mature are transmitted to new cell during cell division, sporogenesis or cell fusion.