Polymorphism of rabies viruses within the phosphoprotein and matrix protein genes

Although the rabies virus P and M genes, encoding the viral phosphoprotein and matrix protein respectively, have been characterised for a few laboratory-adapted strains, there is essentially no information on the variability of these two genes in wild-type rabies viruses. In this study rabies viruses, responsible for epizootics in different wildlife species in three geographically distinct areas of North America, have been characterised at the P and M gene loci. These data reveal that the M gene and its encoded product are much more conserved than the P gene and its encoded phosphoprotein. The latter product harbors two variable domains which contribute to different hydropathy profiles for this protein for each of the rabies virus strains studied. Phylogenetic analysis of the nucleotide sequences generated in this study, together with data generated previously on the N and G genes of these rabies virus strains, indicated that similar evolutionary relationships are predicted regardless of the portion of the viral genome targeted.