Genome organization of the sigma rhabdovirus: six genes and a gene overlap.

The sequence of the sigma virus glycoprotein gene has been reported. We report here the cloning of the cDNAs to four other genes, their physical map on the genome, the sequencing of the intergenic regions, and the determination of the gene junction signals. This analysis reveals unusual traits for a rhabdovirus: four genes map upstream of the glycoprotein gene and the glycoprotein gene overlaps the upstream gene by 33 nucleotides. Northern analysis did not show bicistronic transcripts of the overlapping genes, whereas it revealed bicistronic transcripts of two genes which are separated by a stretch of six nucleotides. This leads us to reconsider the significance of rhabdovirus consensus gene-end sequences and to integrate these data into the models proposed for polymerase functioning.