Arias-Stella reaction

Aphthovirus

Aphthovirus is a genus of viruses in the family Picornaviridae. This genus includes the well-known Foot-and-mouth disease virus (FMDV), which is a significant pathogen affecting livestock worldwide. Aphthoviruses are small, non-enveloped viruses with a single-stranded RNA genome.

Structure

Aphthoviruses are characterized by their icosahedral capsid, which is composed of 60 copies each of four structural proteins: VP1, VP2, VP3, and VP4. The capsid encloses a positive-sense single-stranded RNA genome, which is approximately 8,500 nucleotides in length. The RNA genome is infectious and serves as both the genome and the mRNA for viral protein synthesis.

Genome

The genome of aphthoviruses is organized into a single open reading frame that encodes a polyprotein. This polyprotein is cleaved by viral proteases into structural and non-structural proteins. The structural proteins form the viral capsid, while the non-structural proteins are involved in viral replication and assembly.

Replication Cycle

Aphthoviruses replicate in the cytoplasm of host cells. The replication cycle begins with the attachment of the virus to specific receptors on the host cell surface, followed by entry into the cell. Once inside, the viral RNA is released and translated into a polyprotein, which is subsequently processed into functional viral proteins. The viral RNA is replicated by the viral RNA-dependent RNA polymerase, and new virions are assembled in the cytoplasm before being released to infect other cells.

Pathogenesis

The most notable member of the Aphthovirus genus is the Foot-and-mouth disease virus, which causes foot-and-mouth disease (FMD) in cloven-hoofed animals such as cattle, pigs, sheep, and goats. FMD is highly contagious and can lead to significant economic losses in the livestock industry. The disease is characterized by fever and the formation of vesicles in the mouth and on the feet of infected animals.

Transmission

Aphthoviruses are primarily transmitted through direct contact with infected animals or contaminated materials. The virus can also be spread via aerosols over short distances. Infected animals can shed the virus in saliva, milk, and feces, contributing to the spread of the disease.

Related pages

• Foot-and-mouth disease
• Picornaviridae
• Viral replication

Gallery

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  Electron micrograph of the foot-and-mouth disease virus

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  Structure of the Aphthovirus capsid

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  Genome organization of Aphthovirus

Arias-Stella reaction

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  Arias-Stella Reaction in Endometrium