Mononegavirales

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Mononegavirales is an order of negative-sense RNA viruses with nonsegmented genomes. Some members causing human disease include Ebola virus, respiratory syncytial virus, measles, mumps, Nipah, and rabies. The group also contains important pathogens of nonhuman animals and plants.

The order is divided into eleven families: Artoviridae, Bornaviridae, Filoviridae, Lispiviridae, Mymonaviridae, Nyamiviridae, Paramyxoviridae, Pneumoviridae, Rhabdoviridae, Sunviridae, and Xinmoviridae.

Taxonomy and origin:
- Realm: Riboviria
- Kingdom: Orthornavirae
- Phylum: Negarnaviricota
- Class: Monjiviricetes
- Order: Mononegavirales
- The name comes from Mono (single), negare (negative), and -virales (viral order). The group was established in 1991 and revised multiple times since.

What a Mononegavirus looks like and how it works:
- These viruses attach to a cell, fuse with its membrane, and release their nucleocapsid into the cell.
- The viral RNA-dependent RNA polymerase transcribes the genome into positive-sense mRNAs, which are then translated into proteins.
- Genes closer to the 3' end are copied more often than those near the 5' end, creating a simple transcriptional regime.
- The nucleoprotein is the most abundant protein and helps control when the virus switches from making mRNA to copying the genome.
- Replication makes full-length positive-sense antigenomes, which in turn serve as templates to produce new negative-sense genomes.
- New viral proteins and genomes assemble near the cell membrane and bud off as enveloped virions, ready to infect new cells.

Evolutionary history:
- Mononegavirales has a deep history, with gene remnants (fossils) of these viruses found integrated in the genomes of many animals and even other organisms.
- Bornavirus fossils have been found in bats, fish, hyraxes, marsupials, primates, rodents, ruminants, and elephants.
- Filovirus fossils appear in bats, rodents, shrews, tenrecs, and marsupials.
- A Midway virus fossil exists in zebrafish.
- Rhabdovirus fossils have been found in crustaceans, mosquitoes, ticks, and plants.

The eleven families within Mononegavirales are: Artoviridae, Bornaviridae, Filoviridae, Lispiviridae, Mymonaviridae, Nyamiviridae, Paramyxoviridae, Pneumoviridae, Rhabdoviridae, Sunviridae, and Xinmoviridae.