Muvirales

Muvirales is an order of negative-sense single-stranded RNA viruses within the class Monjiviricetes. This order is part of the phylum Negarnaviricota, which encompasses viruses with genomes composed of negative-sense RNA. The order Muvirales is characterized by its unique genomic and structural features, which distinguish it from other orders within the same class.

Characteristics

Muvirales viruses possess a single-stranded RNA genome that is negative-sense, meaning that the RNA strand cannot be directly translated into proteins by the host cell's ribosomes. Instead, these viruses must first be transcribed into a complementary positive-sense RNA strand by an RNA-dependent RNA polymerase, which is typically encoded by the virus itself.

The virions of Muvirales are generally enveloped, meaning they have a lipid membrane surrounding their protein capsid. This envelope is derived from the host cell membrane and is acquired as the virus buds from the host cell. The envelope contains viral glycoproteins that are crucial for the attachment and entry of the virus into host cells.

Genomic Organization

The genome of Muvirales viruses is typically segmented, with each segment encoding one or more viral proteins. This segmentation allows for reassortment, a process where segments from different viral strains can mix during co-infection of a host cell, potentially leading to new viral variants.

Replication Cycle

The replication cycle of Muvirales begins with the attachment of the virus to a host cell receptor, followed by entry into the cell via endocytosis. Once inside, the viral RNA-dependent RNA polymerase transcribes the negative-sense RNA genome into positive-sense mRNA, which is then translated into viral proteins by the host cell's ribosomes.

The newly synthesized viral proteins and RNA genomes are assembled into new virions, which are then released from the host cell to infect new cells. This release often occurs through budding, which allows the virus to acquire its lipid envelope.

Pathogenesis and Host Range

Muvirales viruses can infect a wide range of hosts, including humans, animals, and plants. The specific host range and pathogenicity depend on the particular virus within the order. Some Muvirales viruses are known to cause significant diseases in their hosts, while others may be relatively benign.

Research and Importance

Research on Muvirales is important for understanding viral evolution, pathogenesis, and the development of antiviral strategies. The segmented nature of their genomes makes them particularly interesting for studies on viral reassortment and genetic diversity.

Also see

• Negative-sense single-stranded RNA virus
• Monjiviricetes
• Negarnaviricota
• Virus classification