Cytoplasmic polyhedrosis virus

Definition

A genus of double-stranded RNA viruses (Cypovirus, family Spinareoviridae) that infect insects exclusively, replicating in the cytoplasm of midgut epithelial cells and forming characteristic proteinaceous occlusion bodies (polyhedra) that protect virions in the environment. Infections typically cause chronic disease with symptoms including larval diarrhea, reduced feeding, developmental stunting, and a distinctive pale blue iridescence visible in the gut.

Etymology

From Greek 'kytos' (cell) + 'plasma' (formed substance), 'poly-' (many) + 'hedra' (seat/base, referring to the faceted crystal structure of occlusion bodies), and Latin 'virus' (poison/venom)

Example

Bombyx mori cypovirus 1, historically called 'cytoplasmic polyhedrosis virus' in sericulture, causes significant economic losses in silkworm rearing when larvae ingest polyhedra-contaminated mulberry leaves, leading to gut dysfunction and failure to spin cocoons.

Synonyms

• Cypovirus

Related Terms

• nucleopolyhedrovirus
• Occlusion body
• baculovirus
• Reoviridae
• Insect virus
• Entomopathogenic virus
• Cytoplasmic inheritance
• Midgut epithelium

Usage Notes

The abbreviation CPV is ambiguous and also used for canine parvovirus and other viruses; prefer 'cypovirus' or full name in entomological contexts. Distinguish from nucleopolyhedroviruses (NPVs, family Baculoviridae), which replicate in the nucleus and have larger, more complex virions. The term originally described the disease syndrome before formal taxonomic establishment of genus Cypovirus in 1999.