2 Structure and Genomic Organization of SV40 and Polyoma Virus

Abstract

Simian virus 40 (SV40) and polyoma virus are among the smallest viruses known. The virions are almost spherical, they contain DNA, and they can induce tumors in animals. These viruses belong to the papovavirus family; the name is derived from pa pilloma virus, po lyoma virus, and va cuolating virus (the old name for SV40) (Melnick 1962). Of the papovaviruses, the best studied are SV40 and polyoma virus. Originally detected as a contaminant in cell-free extracts of tissues of AK mice being used for the transmission of murine leukemia (Gross 1953a,b), polyoma virus first was propagated in vitro by Stewart and Eddy and their coworkers, who used cultures of mouse embryo cells (Stewart et al. 1958; for review, see Stewart 1960). The cytopathic effects of polyoma virus concomitant with productive infections were described by Eddy and Stewart (1959) and Eddy et al. (1960), and the transformation of mouse and hamster cells in culture was observed in several laboratories during the same period (for review, see Gross 1970). The virus was named polyoma (Steward and Eddy 1959) because of its ability to induce a wide range of tumors when injected into animals of several species. SV40 is latent in rhesus monkey kidney and was originally isolated by Sweet and Hilleman (1960) from cultures of rhesus monkey kidney cells of the type being used to produce poliomyelitis vaccines. SV40 was first called vacuolating virus because of its ability to cause multiple vacuoles in the cytoplasm of African green monkey kidney cells, the permissive host of...