Endornaviridae

Caution: The lack of a capsid has led to misclassification of this family into the Baltimore group III: dsRNA viruses due to the accumulation of dsRNA replication intermediates in infected cells.

VIRION

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None reported. No true capsid. The RNA genome is encapsulated along with the viral replicase enzyme.

GENOME

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linear ssRNA(+) genome of about 14 kb to 17.6 kb. A site specific break (nick) is found in the coding strand about 1 to 2 kb from the 5' terminus.

GENE EXPRESSION

The genome encodes for one ORF potentially cleaved in several polypeptides.

REPLICATION

CYTOPLASMIC

  1. Virus penetrates into the host cell.
  2. The viral RNA is translated as a monocistronic mRNA to produce the RdRp.
  3. A dsRNA genome is synthesized from the genomic ssRNA(+), possibly in membrane vesicles.
  4. The dsRNA genome is transcribed/replicated resulting in mRNAs/ssRNA(+) genomes.
  5. The genomic ssRNA is transmitted to new cell via hyphal anastomosis (fungi) or by spores or seeds (fungi or plants).