Transcription and replication initiate at separate sites on the vesicular stomatitis virus genome.

The RNA-dependent RNA polymerase of the nonsegmented negative-strand RNA viruses carries out two distinct RNA synthetic processes: transcription of monocistronic, capped, and polyadenylated subgenomic messenger RNAs, and replication by means of the synthesis of a full-length positive-sense copy of the genome. The template for both processes is the negative-sense genomic RNA tightly encapsidated by the viral nucleocapsid protein. By applying UV transcriptional mapping to engineered variants of vesicular stomatitis virus, we discovered that, in infected cells, transcription and replication are controlled by initiation at different positions on the viral genome.