Metaviridae

Metaviridae is a family of retroviruses that includes the genera Metavirus and Errantivirus. These viruses are characterized by their reverse transcription process, which involves the conversion of their RNA genome into DNA by the enzyme reverse transcriptase. This DNA is then integrated into the host cell's genome, allowing the virus to replicate.

Structure and Genome

Members of the Metaviridae family are enveloped viruses with spherical to pleomorphic shapes. Their capsid is a icosahedron, a shape with 20 faces, each of which is an equilateral triangle. The diameter of the virus particles ranges from 80 to 100 nm.

The genome of Metaviridae is monopartite, linear, and non-segmented. It is composed of single-stranded RNA, which is positive-sense (meaning it can be directly translated into protein). The genome contains two open reading frames (ORFs), which encode for the gag protein and the pol protein.

Replication

Replication of Metaviridae occurs through the process of reverse transcription. The virus enters the host cell and the reverse transcriptase enzyme converts the viral RNA into DNA. This DNA is then integrated into the host cell's genome, where it can be transcribed and translated to produce new virus particles.

Pathogenicity

While some members of the Metaviridae family are pathogenic, causing diseases in their hosts, others are endogenous retroviruses, meaning they are permanently integrated into the host genome and are usually harmless. However, they can become active under certain conditions and cause disease.

See also

• Retrovirus
• Reverse transcription
• RNA virus
• DNA virus