TABLE 1.

Kinetics of labeling of RIs and minus strands by the S1 PI replicon

Labeling methodaLabeling time (h)aS1 RF core, cpm/105 cells% RF cpm in minus strands% of total minus-strand templates
New (labeled)Old (unlabeled)
Pulse1-2829214258
3-4893265248
5-6857265248
7-81,005234654
Accumulation1-2829214258
1-41,664397822
1-62,641428416
1-82,80247946
  • a Times listed for the persistently infected S1 replicon cells are relative to infections of duplicate cultures with SIN HR (p.i.). Pulse labeling used 1-h pulses of [3H]uridine (200 μCi/ml) in the presence of 20 μg/ml of actinomycin D and harvest of the culture at the end of the pulse period. Accumulation or continuous labeling involved the addition of the radiolabeled uridine-containing medium to all cultures at 1 h p.i. and the harvest of individual cultures at the times indicated.