Simian virus 40 induces multiple S phases with the majority of viral DNA replication in the G2 and second S phase in CV-1 cells

The infection of permissive monkey kidney cells (CV-1) with simian virus 40 induces G1 growth-arrested cells into the cell cycle. After completion of the first S phase and movement into G2, mitosis was blocked and the cells e ntered another DNA synthesis cycle (second S phase). Growth-arrested CV-1 c ells replicated significant amounts of viral DNA in the G2 phase with the m ajority of synthesis occurring during the second S phase. When mimosine-blo cked (G1/S) infected cells were released into the cell cycle, a major porti on of the viral DNA was detected in G2 with the largest accumulation in the second S phase. The total DNA produced per infected cell was 10-12C with a pproximately 0.5-2C of viral DNA replicated per cell. Therefore the majorit y of the DNA per cell was cellular, 4C from the first S phase and approxima tely 4-6C from the second cellular synthesis phase. (C) 2000 Academic Press .