Figure 2.

Several vU1 snRNA are transcribed in HeLa cells. (A) ChIP analysis of U1 snRNA and vU1 snRNA genes in HeLa cells with antibodies indicated at right. Error bars in this and subsequent figures represent standard error of at least three repeats. Location of the primers used is indicated on the diagram. The proximal sequence element (PSE), coding and 3′ box are specified by gray and black boxes, respectively, and start of transcription by an arrow. (B) Quantification of vU1 snRNA steady-state levels in HeLa cells, normalized to U1 snRNA. Only reads with two or more nucleotide differences from U1 snRNA were counted toward the vU1 snRNA levels. Experimental data from Fejes-Toth et al. (2009).