Nodaviruses of Insects

Abstract

The study of nodaviruses began with the isolation of nodamura virus (NOV) from mosquitoes in 1956 (Scherer and Hurlbut, 1967; Scherer et al., 1968). The virus drew immediate attention because it uniquely combined the biological property of arthropod transmission to vertebrates with the physical property of resistance to lipid solvents, a characteristic that is now known to indicate the absence of a viral envelope. Molecular studies established that NOV was also unique in its genome structure: two molecules of single-stranded, positive-sense RNA copackaged in spherical virus particles (Fig. 1) (Newman and Brown, 1973, 1977; Clewley et al., 1982). Despite this combination of unusual features, however, the lack of a convenient cell culture system for growing NOV and the absence of antibodies to the virus in human sera, which suggested that it was not naturally transmitted to man, diverted most investigators to more pressing and tractable systems.