Nyavirus
Nyavirus is a genus of negative-strand RNA viruses in the family "Nyamiviridae". Ticks and birds serve as natural hosts. There are four species in this genus. History. "Nyamanini nyavirus" (NYMV) and "Midway nyavirus ("MDWV) were first isolated in 1957 and 1966 respectively. NYMV has been isolated from cattle egrets (species "Bubulcus ibis") and ticks (species "Argas walkerae") in Egypt, India, Nigeria, South Africa, and Thailand. MDWV has been isolated from tick of the genus "Ornithodoros" collected in Midway, Kure and Manana islands and northern Honshu, Japan. Antibodies to this virus have been found in the black-tailed gulls  (species "Larus crassirostris") and black-crowned night herons (species "Nycticorax nycticorax"). Structure. Nyaviruses are enveloped, with spherical geometries. The diameter is around 100 to 130 nm. Genomes are linear, nonsegmented, and around 11.6 kbp in total length. The genome codes for 6 proteins. Their genomes contain six open reading frames. Of these, only two have been assigned a function: the putative nucleocapsid protein and RNA-dependent RNA polymerase. Life cycle. Viral replication is nuclear. Entry into the host cell is achieved by attachment of the viral GP 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. Progeny viruses are released by budding off from the host cell wall. Ticks and birds serve as the natural host. Taxonomy. The genus has four species: