Iridoviridae

Iridoviridae is a family of double-stranded DNA viruses. These viruses infect a wide range of hosts, including insects, fish, and amphibians. The family is named after the iridescent colors that are often observed in infected arthropods, which are caused by the crystalline arrangement of virus particles within the host cells.

The virions of Iridoviridae are large, enveloped, and icosahedral in shape. They possess a linear genome that ranges from approximately 150 to 250 kilobases. The genome encodes for a variety of proteins, including those involved in DNA replication, virion assembly, and host immune evasion.

Replication of Iridoviridae occurs in the cytoplasm of infected host cells. The viruses enter the cell through endocytosis or fusion with the plasma membrane. Once inside, the viral genome is released, and viral DNA replication and protein synthesis take place. New virions are assembled and released from the cell, often leading to cell lysis.

Diseases caused by iridoviruses vary depending on the host. In insects, they can cause significant mortality, particularly in agricultural pests. In fish, iridoviruses can lead to severe disease outbreaks with high mortality rates. Amphibian iridoviruses are also known to cause disease, sometimes referred to as frog virus 3. Research into iridoviruses is ongoing, focusing on understanding their replication cycles, pathogenesis, and potential for biocontrol applications in insect populations.