Rabies virus glycoprotein gene contains a long 3′ noncoding region which lacks pseudogene properties

Abstract

Analysis of a limited number of laboratory strains of rabies virus had demonstrated the presence of a genome region bounded by two transcription termination and polyadenylation-like (TTP) signals (approximately 400 to 450 nucleotides apart) which was located between the end of the glycoprotein (G) coding sequence and the beginning of the L polymerase coding sequence. Although this region had been suggested to represent a remnant or pseudogene ( Ψ), no detailed analysis had been carried out to examine this possibility. Here we present the nucleotide sequence analysis of this genome region for several laboratory rabies virus strains and a large number of diverse rabies viruses detected directly in brain tissue of naturally infected animals. Only one distinct lineage of the laboratory strains and none of the wild-type rabies viruses contained the upstream TTP-like signal, indicating that only the downstream TTP motif is the authentic G mRNA transcription termination and polyadenylation and signal. Phylogenetic analysis of sequence differences provided no evidence of laboratory strains containing the two TTP-like signals being ancestral to any of the viruses possessing only the downstream TTP sequence motif. These data indicate that this region of the rabies virus genome encodes a G mRNA with a long 3′ noncoding region with no evidence of a pseudogene.