Splicing is required for transactivation by the immediate early gene 1 of the Lymantria dispar multinucleocapsid nuclear polyhedrosis virus.

摘要

Lymantria dispar multi-capsid nuclear polyhedrosis virus (LdMNPV) strain Cl 5-6 was used for infection of L. dispar Ld652Y or Spodoptera frugiperda Sf9 cells. Early genes in baculovirus were stimulated by a transcriptional transactivator (IE-1) encoded by the immediate early gene ie-1. Analysis of ie-1 gene expression in Autographa californica multi-capsid nuclear polyhedrosis virus demonstrated that a 2.1-kb transcript was a spliced form of the ie-0 gene. Sequence analysis showed the presence of highly conserved splice donor (ie-0) and splice acceptor (ie-1) sites. The LdMNPV ie-0 was shown to be an essential replication gene in a transient replication assay, whereas the ie-1 gene or the LdMNPV ie-1 promoter were inactive. It is concluded that the inactivity of the cloned LdMNPV ie-1 gene in both transient transcription and replication assays may be due to the experimental system used. The results suggested that splicing was required to obtain an active LdMNPV ie-1 gene product.