In vitro synthesis of large RNAs by an unusual defective interfering particle of vesicular stomatitis virus.

We analyzed an unusual defective interfering (DI) particle of the New Jersey serotype of vesicular stomatitis virus. In vitro transcription experiments demonstrated that this DI particle was unusual in that it transcribed large RNAs in addition to the standard DI leader RNA. S1 nuclease mapping assays indicated that the large transcripts probably resulted from polymerase reinitiation downstream of the DI leader termination site. A sequence related to the Indiana serotype putative polymerase promoter sequence was identified which may regulate the synthesis of the large RNA transcripts.