Mapping the 5' and 3' ends of Autographa californica nuclear polyhedrosis virus polyhedrin mRNA

Abstract

A 102 base cDNA copy of the 5' leader sequence of the Autographa californica nuclear polyhedrosis virus (AcMNPV) polyhedrin mRNA was made using the technique of primer extension with reverse transcriptase. Sequence analysis of the cDNA permitted the exact transcription initiation site of the polyhedrin mRNA to be identified. The sequence data also demonstrated that post-transcriptional processing and subsequent splicing at the 5' end of the mRNA does not occur. Nuclease S1 analysis of the 3' end of the mRNA has demonstrated that transcription terminated 372–376 base pairs from the end of the polyhedrin reading frame. Sequence analysis of AcMNPV DNA identified an AATAAA polyadenylation signal sequence 28 or 32 bases upstream from the end of the polyhedrin gene mRNA. This suggests that the processing of the 3' end of the mRNA occurs in a manner similar to that observed in other virus and cellular systems.