The atypical strategies used for gene expression of Borna disease virus, a nonsegmented, negative-strand RNA virus.

Borna disease virus (BDV) is a neurotropic agent that causes disturbances in movement and behavior in vertebrate host species ranging from birds to primates. Although the virus has not been isolated from human subjects, there is indirect evidence to suggest that humans with neuropsychiatric disorders may be infected with BDV. Recently, virus particles have been isolated and the viral genomic RNA has been cloned. This analysis revealed that BDV is a nonsegmented, negative-strand RNA virus. Unusual features such as RNA splicing, overlap of transcription units and transcription signals, as well as sequence dissimilarity for four of five major open reading frames to genes of other nonsegmented, negative-strand RNA viruses suggest that BDV is likely to represent a new taxon within the order Mononegavirales.