PHYSICOCHEMICAL CHARACTERIZATION OF BOVINE EPHEMERAL FEVER VIRUS AS A MEMBER OF THE FAMILY RHABDOVIRIDAE

This study of the physico-chemical properties of bovine ephemeral fever virus was initiated to establish whether or not it should be classified as a rhabdovirus. In contrast to the regular bullet-shaped morphology of some rhabdovirus the virus particles are often cone-shaped or slight variants from bullet-shaped. The virion contains single-stranded RNA sedimenting at 42S and six proteins with mol. wt. of 164, 101, 64, 53, 43 and 29 x 103. The protein P101 is located on the surface of the virus and is glycosylated. It is removed by treatment of the virus particles with trypsin. Protein P64, the nucleoprotein, was found to be a phosphoprotein, like the N protein of rabies virus, whereas in vesicular stomatitis virus NS is the phosphorylated protein. Virus harvests contain defective-interfering particles. The particles are short cone-shaped forms about one-third the length of the infectious virion and similar in morphology to defective-interfering particles of vesicular stomatitis virus. These particles interfere with the replication of bovine ephemeral fever virus but not with the Indiana serotype of vesicular stomatitis virus. They contain single-stranded RNA sedimenting at 18 to 20S. The particles appear to have a protein composition identical to that found in the virus particle. The physico-chemical properties of bovine ephemeral fever virus justify its inclusion in the family Rhabdoviridae. The protein composition differs in detail from that found for vesicular stomatitis and rabies viruses, but is similar to that found for Obodhiang and kotonkan, two rabies serogroup viruses isolated from insects in Africa.