Project name: White spot syndrome virus

Description: Description of Nimaviridae adapted from ICTVdb Virion Properties Morphology Virions consist of an envelope, a nucleocapsid, and appendages. Virus capsid is enveloped by a trilaminar loose fitting envelope. Virions are ovoid, or bacilliform to ellipsoid, have protrusions that extend through the envelope and have a thread- or tail-like polar extension at one end. Virions measure 120-150 nm in diameter; 270-290 nm in length. A regular capsid structure is present. Capsid elongated and exhibits regular symmetry. The nucleocapsid is rod-shaped; has a tight-fitting capsid with a cross-hatched appearance with a length (of isolated nucleocapids) with a length of 300-350 nm. Nucleocapsid contains DNA-protein core. Physicochemical and Physical Properties Virions have a buoyant density in CsCl of 1.22 g cm-3 (virions), or 1.31 g cm-3 (nucleocapsids). Virions are sensitive to treatment with detergents. Nucleic Acid The genome is not segmented and contains a single molecule of circular double-stranded DNA. The complete genome is 300000 nucleotides long. The genome has a guanine + cytosine content of 41 %. Proteins Proteins have been characterized and functions are assigned to them. The viral genome encodes structural proteins, or non-structural proteins. Virions consist of at least 5 structural protein(s) (major and an unknown number of minor located in the envelope and nucleocapsid. The viral envelope contains 2 integral membrane proteins. Structural Proteins: Envelope protein VP28 and VP19. Nucleocapsid protein VP26, VP24 and VP15. Lipids Lipids are present and located in the envelope. The composition of viral lipids is not known.

Last updated: 2006-10-10