Vesiculovirus replication is well studied and has served as model for replication of the rhabdoviruses. Transcription begins at a single entry site at the 3 end of the genome with each gene expressed as a capped and polyadenylated monocistronic mRNA. The first transcript is the 3leader, which is neither capped nor polyadenylated. It is transported to the nucleus where it inhibits host cell transcription. The leader transcript is followed by the N mRNA, which is capped during synthesis by the virion polymerase complex (composed of N, P and L). The intergenic sequence
(5-AGUUUUUUUCAUA-3) signals polyadenylation, termination and re-initiation of transcription in decreasing amounts as the polymerase complex moves away from the single entry site.
Therefore, the gene order (i.e. 3 NPMGL 5) provides an efficient way of regulating gene
expression, by which proteins necessary in larger amounts (such as N) are located near the 3 end and are transcribed in larger amounts and those needed in smaller amounts are located towards the5 end and are transcribed less frequently.