FIG. 5.

Transcription of ribosomal genes during NER in wt, rad1Δ, and rad14Δ mutant strains. Nuclei were isolated from nonirradiated (−UV) cells and from UV-irradiated cultures at different repair times. After incubation under TRO reaction conditions, the purified radiolabeled RNA was used as a probe to hybridize the membrane-bound rDNA. Membranes were then exposed to phosphorimager screens, and the rDNA signals were normalized to the corresponding signals for the external standard (13). Transcription of the nonirradiated cultures is given an arbitrary value of 1, and transcription of other samples is expressed relative to this value. Black bars, wt strain; gray bars, rad1Δ strain; hatched bars, rad14Δ strain. Data are the means ± 1 SD of three independent experiments for wt and the average of two independent experiments for rad1Δ and rad14Δ cells.