Chrysoviridae

Chrysoviridae

The Chrysoviridae is a family of double-stranded RNA viruses that primarily infect fungi. Members of this family are characterized by their multipartite genome, which is typically composed of four segments. These viruses are non-enveloped and have an icosahedral capsid structure.

Taxonomy

The family Chrysoviridae is part of the order Martellivirales. It includes several genera, with the type species being Penicillium chrysogenum virus. The family is named after the Greek word "chrysos," meaning "gold," reflecting the golden color of the fungal host from which the type species was first isolated.

Structure

Chrysoviruses have a simple, non-enveloped icosahedral capsid with a diameter of approximately 35 nm. The capsid is composed of a single type of protein, and the genome is divided into four linear double-stranded RNA segments, each encoding a single protein. These segments are typically designated as RNA1, RNA2, RNA3, and RNA4.

Genome

The genome of chrysoviruses is multipartite, consisting of four segments:

• RNA1: Encodes the RNA-dependent RNA polymerase (RdRp), which is essential for viral replication.
• RNA2: Encodes a capsid protein that forms the viral capsid.
• RNA3: Encodes a protein of unknown function, often referred to as a "non-structural protein."
• RNA4: Encodes another protein of unknown function, which may play a role in the virus-host interaction.

Replication

Chrysoviruses replicate in the cytoplasm of their fungal hosts. The replication cycle begins with the transcription of the viral RNA segments by the RdRp. The newly synthesized RNA segments are then encapsidated into new virions, which are released upon cell lysis or through other mechanisms that are not yet fully understood.

Host Range

Chrysoviruses primarily infect fungi, including both pathogenic and non-pathogenic species. They have been isolated from a variety of fungal hosts, including species of the genera Penicillium, Aspergillus, and Fusarium. The impact of chrysovirus infection on the host can vary, ranging from asymptomatic to causing significant changes in host physiology and morphology.

Significance

The study of chrysoviruses is important for understanding virus-host interactions in fungi, which can have implications for agriculture and biotechnology. Some chrysoviruses have been shown to alter the virulence of their fungal hosts, potentially offering a means of biological control for fungal pathogens.

Also see

• Mycovirus
• Double-stranded RNA virus
• Fungal virology
• Martellivirales