Лиссавирустар туқымы: генетикалық және географиялық зерттеулер

Genus of viruses

the rabiform virus

Lyssavirus (from the Greek λύσσα lyssa "rage, fury, rabies" and the Latin vīrus) is a genus of RNA viruses in the family Rhabdoviridae, order Mononegavirales. Mammals, including humans, can serve as natural hosts. The genus Lyssavirus includes the rabies virus traditionally associated with the disease of the same name.

Phylogenetic studies suggest that the original hosts of these viruses were bats. However, the recent discovery of lyssavirus sequences from amphibians and reptiles challenges the mammalian origin of lyssaviruses. The greater antigenic diversity of lyssaviruses from Africa has led to the assumption that Africa was the origin of these viruses. An examination of 153 viruses collected between 1956 and 2015 from various geographic locations has instead suggested a Palearctic origin (85% likelihood) for these viruses. Date estimates (95% likelihood) for the most recent common ancestor were very broad – between 3,995 and 166,820 years before present – which suggests there is further work to be done in this area. Although bats evolved in the Palearctic, their origins antedate that of the lyssaviruses by millions of years, which argues against their co speciation. The evolution rate in the N gene in the Africa 2 lineage has been estimated to be 3.75×10−3 substitutions per site per year. This rate is similar to that of other RNA viruses.

Viral replication is cytoplasmic. Entry into the host cell is achieved by attachment of the viral G glycoproteins to host receptors, which mediates clathrin mediated endocytosis. Replication follows the negative stranded RNA virus replication model. Negative stranded RNA virus transcription, using polymerase stuttering, is the method of transcription. The virus exits the host cell by budding and by tubule guided viral movement. Wild mammals, especially bats and certain carnivores, serve as natural hosts. Transmission routes are typically via bite wounds.

Classic rabies virus is prevalent throughout most of the world and can be carried by any warm blooded mammal. The other lyssaviruses have much less diversity in carriers. Only select hosts can carry each of these viral species. Also, these other species are particular only to a specific geographic area. Bats are known to be an animal vector for all identified lyssaviruses except the Mokola virus.