Ambidensovirus

The virus genus Ambidensovirus belongs to the Densovirinae subfamily of the family Parvoviridae. Members of this genus are single-stranded DNA viruses. This genus infects invertebrates, including insects, crustacea and echinoderms. There are currently eleven species in this genus including the type species Lepidopteran ambidensovirus 1. Group: ssDNA Virions consist of non-enveloped capsids that have a round appearance and display icosahedral symmetry. The virions each have an isometric (and therefore spherical) nucleocapsid with a diameter of either 18–22 nm or 20–26 nm. Sixty capsomers are present in each capsid. The structure of each capsomer is described as 'a quadrilateral 'kite-shaped' wedge'; the surface is said to have a rough appearance with small projections. The center of capsids are sometimes visualized as appearing dark due to stain penetration in preparations where only a single species is retrieved. The virions do not appear to contain lipids. The buoyant density (in CsCl) of the virions is 1.4–1.44 g cm−3. Ambidensoviruses have non-segmented genomes that contain a 5-6 kb linear ambisense single-stranded DNA and long inverted terminal repeats (550 bp). The ambisense genome encodes proteins on both the positive and negative sense strands, Densoviruses use transcriptional regulation and post-transcriptional modification to produce different nonstructural proteins and structural proteins (VP). Viral replication is nuclear. Entry into the host cell is achieved by attachment to host receptors, which may be mediated by clathrin-mediated endocytosis or clathrin-independent dynamin-dependent endocytosis. Replication follows the rolling-hairpin model. DNA-templated transcription, with some alternative splicing mechanism is the method of transcription. Insects serve as the natural host.