Expression of densonucleosis virus GmDNV in Galleria mellonella larvae: Size analysis and in vitro translation of viral transcription products

The RNA of densonucleosis virus type 1 (GmDNV), isolated from GmDNV-infected Galleria mellonella larvae, was shown by Northern blotting to contain five polyadenylated, viral-specific RNA species with sizes of 1.8, 2.4, 3.5, 4.0, and 5.0 kb. Poly(A)-containing RNA from whole larvae and hybrid-selected viral RNA were translated in a rabbit reticulocyte lysate system and the translation products were coelectrophoresed with proteins extracted from CsCl-purified virus. All four virion-associated proteins, namely p49, p55, p65, and p94, were present in the in vitro-translated products. However, in the majority of the experiments the most abundant translation product was a 30K polypeptide which is absent from virion extracts. The most abundant viral protein is p49, and the 49K polypeptide was also the most abundant translation product in about 30% of the preparations. The 1.8 kb transcript, which constitutes about half of the total viral RNA, is only slightly larger than the template required for a 30K polypeptide, suggesting that the latter may be a primary translation product of the smallest RNA transcript. The similarities in gene expression between densoviruses and mam malian parvoviruses are discussed.