Effect of adenovirus on host cell DNA synthesis in synchronized cells

Viral and cellular DNA synthesis were examined in synchronized HeLa cells infected at various stages in the cell cycle with adenovirus type 2. Viral DNA synthesis began approximately 9 hours after infection, whether cells were infected during S or G₁. When viral DNA was synthesized during G₁, premature replication of cellular DNA did not occur, and its subsequent initiation at the beginning of S was prevented. When viral DNA synthesis began after the onset of S, cellular DNA replication was partially, but not completely, inhibited. Nucleohistones were synthesized only in association with cellular DNA.