Nudiviruses are large and rod-shaped viruses with a circular, double stranded DNA genome. They are related to the baculoviruses and like these infect arthropods, particularly insects (Wang et. al., 2007a). They share 20 core genes with baculoviruses. However, they are currently no longer regarded as members of the family Baculoviridae and are considered to be a sister group of these (Mayo, 1995).

Taxonomy

In 2007, the genus Nudivirus has been proposed to include viruses similar to the Oryctes rhinoceros virus (Wang et. al., 2007b).

Virology

This genus is characterized by rod-shaped and enveloped nucleocapsids and its members replicate in the nucleus of infected host cells. However, the viruses are not embedded in inclusion bodies (crystallized proteins) like the baculoviruses. All sequenced nudiviruses have 33 open reading frames

Open reading frame

In molecular genetics, an open reading frame is a DNA sequence that does not contain a stop codon in a given reading frame.Normally, inserts which interrupt the reading frame of a subsequent region after the start codon cause frameshift mutation of the sequence and dislocate the sequences for stop...

 in common, 20 of them are homologous to baculovirus core genes involved in RNA transcription, DNA replication, virion structural components and other functions. Nudiviruses and baculoviruses appear to be derived from a common ancestor and evolutionarily related to other large DNA viruses (Wang et. al., 2009).

Host-virus relations

• Gryllus bimaculatus nudivirus - black cricket (Teleogryllus commodus)
• Helicoverpa zea nudivirus 1 - cotton bollworm
• Helicoverpa zea nudivirus 2 - cotton bollworm
• Penaeus monodon nudivirus - a shrimp
• Oryctes rhinoceros nudivirus - rhinoceros beetle (Dynastinae species)

Relation to polydnaviruses in parasitic wasps

Parasitic wasps contain particles of polydnaviruses from portions of a nudivirus which have become part of the wasp genome. The genes help form particles like virions which are injected into the host larvae of the wasp and suppress a defensive response. The wasp eggs can then develop and parasitize the larva  (Stoltz et al., 2009).