Articulavirales

Articulavirales

The order Articulavirales is a group of viruses that are characterized by their segmented, negative-sense single-stranded RNA genomes. This order includes several families of viruses that are known to infect a wide range of hosts, including humans, animals, and plants. The most well-known family within this order is the Orthomyxoviridae, which includes the influenza viruses.

Characteristics

Articulavirales viruses are distinguished by their segmented RNA genomes, which means that their genetic material is divided into separate pieces, each encoding one or more proteins. This segmentation allows for genetic reassortment, a process that can lead to the emergence of new viral strains with novel properties. The RNA genome is of negative polarity, meaning it must be transcribed into a positive-sense RNA before it can be translated into proteins by the host cell machinery.

Structure

The virions of Articulavirales are typically enveloped, meaning they have a lipid membrane surrounding their protein capsid. The envelope is derived from the host cell membrane and contains viral glycoproteins that are essential for the virus's ability to infect host cells. These glycoproteins are responsible for binding to host cell receptors and facilitating the entry of the viral genome into the host cell.

Replication Cycle

The replication cycle of Articulavirales begins with the attachment of the virus to a host cell via its surface glycoproteins. Following attachment, the virus is internalized, and the viral RNA segments are released into the host cell cytoplasm. The viral RNA-dependent RNA polymerase transcribes the negative-sense RNA into positive-sense mRNA, which is then translated into viral proteins. New viral RNA segments are synthesized and assembled into progeny virions, which are released from the host cell to infect new cells.

Families

The order Articulavirales includes several families, the most notable of which are:

• Orthomyxoviridae: This family includes the influenza viruses, which are significant pathogens in humans and animals. Influenza viruses are responsible for seasonal flu epidemics and occasional pandemics.
• Arenaviridae: Although not as well-known as Orthomyxoviridae, this family includes viruses that can cause hemorrhagic fevers in humans.

Pathogenicity

Viruses within the Articulavirales order can cause a range of diseases, depending on the specific virus and host. Influenza viruses, for example, cause respiratory illness in humans, ranging from mild to severe. Some strains can lead to pandemics, such as the 1918 Spanish flu.

Also see

• Virus classification
• RNA virus
• Influenza
• Viral replication