Quadrivirus

VIRION

Non-enveloped capsid about 48 nm in diameter. The four genomic segments are possibly encapsidated separately.

GENOME

Segmented linear dsRNA genome about 16.8 kb: 4 segments encoding for 4 proteins.

GENE EXPRESSION

Each genomic segment encodes for a single protein.Segment 2 and 4 structural proteins may be processed during virion assembly.

REPLICATION

CYTOPLASMIC

  1. Virus penetrates into the cytoplasm.
  2. 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.
  3. (+)RNAs are encapsidated in virion particle, in which they are transcribed to give RNA (-) molecules with which they become base-paired to produce dsRNA genomes.
  4. Mature virions are transmitted to new cell by cytoplasmic exchange, sporogenesis or Hyphal anastomosis.