Non enveloped, icosahedral, non-turreted virion with a triple capsid structure, about 90-95 nm in diameter. The intermediate capsid has a T=13 icosahedral symmetry, the inner capsid a T=2* icosahedral symmetry.



Segmented linear dsRNA genome. Contains 11 segments encoding for at least 11 proteins. Segment 1 of MpRV is 5.8 kb long, the longest segment of any of the characterized reoviruses.


The dsRNA genome is never completely uncoated, to prevent activation of antiviral state by the cell in response to dsRNA. The viral polymerase synthesizes a capped mRNA from each dsRNA segment. This capped mRNA is translocated to the cell cytoplasm where it is translated.



  1. Attachment to host receptors probably mediates endocytosis of virus into host cell.
  2. Particles are partially uncoated in endolysosomes, but not entirely, and penetrate in the cytoplasm.
  3. Early transcription of the dsRNA genome by viral polymerase occurs inside this sub-viral particle (naked core), so that dsRNA is never exposed to the cytoplasm.
  4. Full-length plus-strand transcripts from each of the dsRNA segments are synthesized. These plus-strand transcripts are used as templates for translation.
  5. Viral proteins and genomic RNAs aggregates in cytoplasmic viral factories.
  6. (+)RNAs are encapsidated in a sub-viral particle, in which they are transcribed to give RNA (-) molecules with which they become base-paired to produce dsRNA genomes.
  7. The capsid is assembled on the sub-viral particle.
  8. Mature virions are released presumably following cell death and associated breakdown of host plasma membrane.

Matching UniProtKB/Swiss-Prot entries

11 entries grouped by strain (browse by keywords)

11 entries

Micromonas pusilla reovirus (isolate Netherlands/2005) (MpRV) reference strain

VP10_MPRVN Uncharacterized protein VP10
NS2_MPRVN Putative non-structural protein 2 (NS2)
RDRP_MPRVN RNA-directed RNA polymerase VP2 (EC
NS1_MPRVN Putative non-structural protein 1 (NS1)
VP6_MPRVN Uncharacterized protein VP6
VP4_MPRVN Uncharacterized protein VP4
VP9_MPRVN Putative outer capsid protein VP9
VP5_MPRVN Putative outer capsid protein VP5
VP1_MPRVN Uncharacterized protein VP1
CAPSD_MPRVN Major inner capsid protein VP3
VP11_MPRVN Uncharacterized protein VP11