Patterns of Simian Virus 40 DNA Transcription after Acute Infection of Permissive and Nonpermissive Cells

Abstract

Small amounts of fractionated, denatured, 32P-labeled DNA /Ci/ml), as well as fresh phosphate-free Eagle's medium, were added 24-30 hr after infection. Virus was prepared (6) from cells and medium 7-8 days later. SV40 DNA I was isolated from purified virus after it was treated with 1% sodium dodecyl sulfate for 30 min at 500 and centrifuged isopycnically in CsCl in the presence of ethidium bromide (200,ug/ml) (7,3). Labeled DNA preparations had specific activities from 0.7 to 2.6 X 101 cpm/,ug. The SV40 [32P]DNA I was mechanically sheared (50,000 psi) in a Ribi Cell Fractionator to a molecular size of about 3.1 X 105 daltons (4).

Altered Patterns of Protein Synthesis in Infection by SV40 Mutants

“…The viral gene(s) expressed early in productive infc~ction are the only gene(s) expressed in transforming infection (Khoury et al 1972;Sambrook et al 1972). Although several virus-induced early antigens have been identified in infected cells (Black et al 1963;Lewis and Rowe 1971), only one early gene (gene A) has been detected by genetic techniques (Tegtmeyer and Ozer 1971;Chou and Martin 1974).…”

Effect of Azacytidine in SV40-Infected BSC-1 Cells

“…The profile of hybridized radioactiv ity was coincident with the total radioactivity in the I9S and I6S peaks and accounted for approximately 8.9% of total. Since our hybrid ization efficiency against cRNA (kindly pro vided by Dr. George Khoury [9]) was 30% [un published results], the viral-specific RNA in the 19S and I6S RNA region accounted for approximately 28% of the total radioactivity. Other experiments (not shown) gave values as high as 36% viral-specific RNA.…”

Increased DNA-Dependent RNA Polymerase Activity from CV-1 Cells Productively Infected by SV40

“…In permissive host cells, two classes of viral-specific RNA are synthesized at different times during the viral replication cycle [1][2][3][4]. The shift in synthesis from early to late RNA sequences occurs at about the same time as SV40 DNA synthesis (12-18 h).…”