The Isolation and Characterization of a Virus from Oryctes rhinoceros

Abstract

SUMMARY A virus was isolated from larvae of the rhinoceros beetle (Oryctes rhinoceros), which resembled particles observed in thin sections of the midgut epithelium of diseased insects. The virus was rod-shaped, enveloped, and measured approx. 220 × 120 nm. Purified particles had a density in sucrose of 1.18 g/ml and contained eleven protein components as determined by electrophoresis in 10% polyacrylamide gels. The two major proteins were of low mol. wt. (9.7 and 12.5 × 103). The nucleic acid had a density in caesium chloride characteristic of double-stranded DNA, with an estimated guanosine:cytosine content of 43%. A small proportion (9%) of the DNA was present as covalently-closed molecules. The virus DNA contained molecules with different sedimentation velocities, the major component having a sedimentation coefficient of 57.2S and an estimated mol. wt. of 87 × 106. It is proposed that this virus be included in the Baculovirus group.