The family Rhabdoviridae comprises approximately 75 viruses infecting vertebrates, invertebrates and plants. The main characteristics of the member viruses are: (i) the viruses infecting vertebrates and invertebrates are bullet-shaped and the viruses infecting plants are usually bacilliform; (ii) the viruses have particle lengths varying from 130 to 380 nm and widths varying from 60 to 95 nm; (iii) the viruses possess unit-membrane envelopes from which protrude spikes 5 to 10 nm long; (iv) the viruses have precisely coiled helical nucleocapsids with a diameter of approx. 50 nm; (v) most of the viruses which have been studied contain 5 proteins; the prototype, vesicular stomatitis virus, contains proteins designated L (large), G (glycoprotein), N (nucleoprotein), NS (nonstructural) and M (matrix); N or NS is phosphorylated in most members which have been studied; (vi) the viruses contain single-stranded RNA which is transcribed into several messenger RNA species with sizes corresponding to the structural proteins; (vii) the nucleocapsid contains the RNA-dependent RNA polymerase and is infectious; and (viii) many of the viruses produce morphologically distinct defective-interfering (T) particles.