RNA synthesis in the TbTRF4 RNAi cell line. (A) Dot blot hybridization with RNA synthesized in uninduced cells (−) or after 1 or 2 days (1d and 2d) of TET induction. Two different exposure times are shown for the SL RNA hybridization. rDNA, rRNA genes; tub, tubulin; pBS, plasmid vector control. (B) Quantitation of three independent experiments as shown in panel A. Percent RNA synthesis compared to no induction (100%) (black bars) is shown after 1 day (bars 1, or grey bars) or 2 days of induction (bars 2, or white bars). Since the values for the U2 and U6 snRNA genes were almost identical, they are shown together. tub, tubulin gene probe (see reference 10 for a description of the plasmids); rDNA, rRNA genes.