Mononegavirales

Mononegavirales is an order of enveloped, nonsegmented, negative-sense RNA viruses that infect a wide range of hosts, including humans and animals. Members share a cytoplasmic replication cycle that relies on a nucleoprotein-bound genome and a viral RNA-dependent RNA polymerase to produce both mRNA and replicative copies from a single, continuous RNA segment.

Taxonomy within Mononegavirales comprises six families: Bornaviridae, Filoviridae, Nyamiviridae, Paramyxoviridae, Pneumoviridae, and Rhabdoviridae. These families encompass a variety of clinically and ecologically important viruses, some of which cause substantial disease in humans and animals, while others have more restricted host ranges. Notable members include Rabies virus (Rhabdoviridae), Ebola and Marburg viruses (Filoviridae), Measles and Mumps viruses (Paramyxoviridae), Respiratory syncytial virus and Human metapneumovirus (Pneumoviridae), and Borna disease virus (Bornaviridae).

Virology and genome organization are broadly similar across the order. Virions are typically enveloped and possess a helical nucleocapsid. The genome is a single linear molecule of negative-sense RNA, usually organized into a set of conserved genes such as nucleoprotein (N), phosphoprotein (P), matrix protein (M), and polymerase (L), with surface glycoproteins (G, F, or GP) encoded to mediate entry. Gene arrangement and the presence of accessory proteins vary by family. Transcription generally yields separate monocistronic mRNAs, followed by replication to produce antigenomes for genome synthesis. Lifecycle processes include attachment and fusion mediated by glycoproteins, cytoplasmic transcription and replication, and budding or release from the plasma membrane.

Mononegavirales is studied for its public health relevance, viral evolution, and as a model for negative-sense RNA virus biology, with several members targeted by vaccines or therapeutics.