Notes on Genus: Cypovirus


Type member: Cypovirus 1


General Description

This is one of the animal virus genera in the family Reoviridae. Members have 10 segments and particles less than 70 nm in diameter and are only known to infect arthropods. The name derives from cytoplasmic polyhedrosis, which occurs in infected cells.


Virions isometric (icosahedral), 55-69 nm in diameter, with a single capsid shell and hollow surface spikes.


Linear, double stranded RNA in 10 segments. Each virion contains a single copy of the entire genome. Total genome up to c.25000 nucleotides long.

Genus Genomic Organization

Each segment has a single ORF. The major core protein is encoded by the largest segment and the RNA polymerase by the second segment. The functions of most of the other encoded proteins have still to be determined.

Type Member Genomic Organization

  • Segment 1 (4164 nt) encodes the major core protein of 148.2 kDa
  • Segment 2 (3853 nt) encodes the RNA polymerase (138.8 kDa)
  • Segment 3 (3846 nt) encodes a protein of 140.1 kDa
  • Segment 4 (3262 nt) encodes a virion surface protein of 119.4 kDa
  • Segment 5 (2851 nt) encodes a non-structural protein of 100.2 kDa
  • Segment 6 (1792 nt) encodes a virion protein of 63.5 kDa
  • Segment 7 (1501 nt) encodes a non-structural protein of 49.8 kDa
  • Segment 8 (1332 nt) encodes a protein of 43.9 kDa
  • Segment 9 (1187 nt) encodes a non-structural protein of 35.7 kDa with dsRNA binding activity
  • Segment 10 (944 nt) encodes the polyhedrin protein (28.5 kDa)