Mesoniviridae

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Mesoniviridae
Kingdom:
Phylum:	Lenarviricota
Class:	Flasuviricetes
Order:	Amarillovirales
Family:	Mesoniviridae

Mesoniviridae is a family of positive-sense single-stranded RNA viruses that primarily infect insects. This family is part of the order Amarillovirales and is known for its unique genomic and structural characteristics. The family name is derived from the Greek word "mesos," meaning "middle," reflecting its intermediate genome size compared to other related virus families.

Taxonomy

The family Mesoniviridae contains a single genus, Alphamesonivirus. Within this genus, several species have been identified, including:

• Alphamesonivirus 1
• Alphamesonivirus 2

These viruses have been isolated from various mosquito species, indicating their role as insect-specific viruses.

Genome and Structure

Mesoniviridae viruses possess a positive-sense single-stranded RNA genome that is approximately 20 kilobases in length. The genome encodes several non-structural proteins involved in replication, as well as structural proteins that form the viral capsid. The virions are enveloped and spherical, with a diameter of about 60-80 nm.

The genome organization of Mesoniviridae is similar to other nidoviruses, with conserved open reading frames (ORFs) that encode the replicase polyprotein, followed by structural proteins. The replicase polyprotein is processed into functional units by viral proteases.

Replication Cycle

The replication cycle of Mesoniviridae begins with the attachment of the virus to the host cell surface receptors, followed by entry into the cell. Once inside, the viral RNA is released into the cytoplasm, where it serves as a template for translation of the viral replicase proteins. These proteins then mediate the synthesis of a complementary negative-sense RNA strand, which serves as a template for the production of new positive-sense genomic RNA.

The newly synthesized genomic RNA is packaged into virions, which are then released from the host cell to infect new cells. The replication cycle is completed within the cytoplasm of the host cell.

Ecology and Host Range

Mesoniviridae viruses are primarily associated with mosquitoes, and their ecological role is not fully understood. They are considered insect-specific viruses, with no known vertebrate hosts. This host specificity suggests a potential role in regulating mosquito populations or interactions with other mosquito-borne viruses.

Research and Significance

Research on Mesoniviridae is ongoing, with studies focusing on their molecular biology, ecology, and potential applications in controlling mosquito populations. Understanding the interactions between Mesoniviridae and their mosquito hosts could provide insights into the evolution of insect-specific viruses and their impact on ecosystems.

Also see

• Nidovirales
• Positive-sense single-stranded RNA virus
• Insect virology
• Mosquito-borne diseases