Iridovirus

Iridovirus is a genus of viruses in the family Iridoviridae. Iridoviruses are large, icosahedral viruses that infect invertebrates and poikilothermic vertebrates. The name "Iridovirus" is derived from the Latin word "iris", meaning rainbow, due to the iridescent colors displayed by the infected host tissues when viewed in sunlight.

Structure

Iridoviruses are non-enveloped, with icosahedral geometries, and T=147 symmetry. The diameter is around 120-350 nm. Genomes are linear, around 103-220kb in length. The genome codes for 100-200 proteins.

Life Cycle

Viral replication is nuclear. Entry into the host cell is achieved by attachment of the viral proteins to host glycosaminoglycans (GAGs), which mediates endocytosis of the virus into the host cell. Replication follows the DNA strand displacement model. DNA-templated transcription, with some alternative splicing mechanism is the method of transcription. The virus exits the host cell by nuclear pore export, and budding. Invertebrates and poikilothermic vertebrates serve as the natural host.

Pathology

Iridoviruses can cause significant disease in their hosts. In insects, infection can lead to paralysis and death. In fish, iridoviruses can cause systemic infections, leading to high mortality rates. In amphibians, iridoviruses have been associated with population declines worldwide.

Taxonomy

The genus Iridovirus contains the following species:

• Invertebrate iridescent virus 1
• Invertebrate iridescent virus 2
• Invertebrate iridescent virus 3
• Invertebrate iridescent virus 6
• Lymphocystis disease virus 1
• Lymphocystis disease virus 2
• Lymphocystis disease virus 3
• Lymphocystis disease virus 4

See Also

• Virology
• Icosahedral symmetry
• Invertebrate pathology
• Poikilotherm