Major EB virus-specific cytoplasmic transcripts in a cellular clone of the HR-1 Burkitt lymphoma line during latency and after induction of viral replicative cycle by phorbol esters.

We have estimated by the Northern blotting technique the size and genome location of major viral RNA transcripts found in the same cell line when the Epstein-Barr virus (EBV) genome was latent, and 48 hr after it was induced to replicate by treatment with 12-O-tetradecanoylphorbol acetate (TPA). A cellular subclone of the P3J-HR-1 line designated GG68-13 made these studies possible. Less than 1% of GG68-13 cells spontaneously synthesize viral antigens, whereas more than 80% of the cells enter the viral replicative cycle after exposure to TPA. In the absence of TPA six clearly resolved mRNA's, derived from scattered regions of the genome, are seen and at least four poorly resolved mRNA's map to BamHI fragment W, the internal repeat. Following treatment with the drug, 54 mRNA's have been identified, 28 of which are prominent. The mRNA's identified during latency are also synthesized, but in greater amounts, during viral replication. However, EBV-encoded small RNA's seem to be more abundant during latency than during viral synthesis.