Ascovirus is a family of double strand DNA viruses that infect primarily invertebrates. Currently only a single genus in this family is recognised: Ascovirus.
Six species in this genus are currently known. The type species is Spodoptera frugiperda ascovirus 1a which infects the army worm (Spodoptera frugiperda). Other species include Spodoptera frugiperda ascovirus-1d.
The virions consist of an envelope, a core, and an internal lipid membrane associated with the inner particle. The virus capsid is enveloped and measures 130 nm in diameter, and 200-240 nm in length. Virions are bacilliform, ovoid, and allantoid.
These viruses infect immature stages of the order Lepidoptera, in which they cause a chronic, fatal disease. They are transmissed by endoparasitic wasps and the host develops a unique cytopathology that resembles apoptosis. Cell infection induces apoptosis and in some species is associated with synthesis of a virus-encoded executioner caspase and several lipid-metabolizing enzymes. After infection the host cell DNA is degraded, the nucleus fragments and the cell then cleaves into large virion-containing vesicles. Synthesis of viral proteins results in the rescue of developing apoptotic bodies that are converted into large vesicles in which virions accumulate and continue to assemble. In infected larvae, millions of these virion-containing vesicles begin to disperse from infected tissues 48–72 hours after infection into the haemolymph, making it milky white, a characteristic of this disease. The circulation of virions and vesicles in the blood facilitates mechanical transmission by parasitic wasps.
^ICTVdB Management (2006). 00.082.0.01. Ascovirus. In: ICTVdB - The Universal Virus Database, version 4. Büchen-Osmond, C. (Ed), Columbia University, New York, USA
^Xue JL, Cheng XW (2011) Comparative analysis of a highly variable region of the genomes between Spodoptera frugiperda ascovirus 1d (SfAV-1d) and SfAV-1a. J Gen Virol
^Bideshi DK, Demattei MV, Rouleux-Bonnin F, Stasiak K, Tan Y, Bigot S, Bigot Y, Federici BA (2006) Genomic sequence of Spodoptera frugiperda Ascovirus 1a, an enveloped, double-stranded DNA insect virus that manipulates apoptosis for viral reproduction. J Virol. 80(23):11791-1805.
^ abFederici BA, Bideshi DK, Tan Y, Spears T, Bigot Y (2009) Ascoviruses: superb manipulators of apoptosis for viral replication and transmission. Curr Top Microbiol Immunol 328:171-196.