Extended Data Fig. 1: Additional characterization of Pol I and Pol II occupancy at rDNA IGSs.
From: Nucleolar RNA polymerase II drives ribosome biogenesis
a, Organization of human rDNA repeats. At each rDNA unit, Pol I transcribes an rRNA gene encoding a 47S pre-rRNA that is processed to remove transcribed spacers, such as the 5′-ETS, and generate 18S, 5.8S and 28S rRNA molecules. The IGS constitutes the bulk of each rDNA unit. Ter, rRNA gene terminator. b, c, Specificity controls indicating that targeting Pol II for degradation with a 12-hour α-amanitin (AMN) treatment lowers anti (α)-Pol II pS2 signals in both immunofluorescence (b) and immunoblotting (c). Actin was used as a control for immunoblotting. For gel source data, see Supplementary Fig. 1. d, ChIP showing Pol II pS5 enrichment across rDNA. e, f, The enrichment of active Pol II pS2 and pS5 at rDNA IGS sites is higher than at LINE1 but lower than at β-actin sites. g–k, ChIP experiments showing the enrichment of the indicated proteins across rDNA. l, Comparison of the enrichment of RNA Pol II and Pol I across rDNA reveals the relative overrepresentation of Pol II across IGSs only. b–l, HEK293T (b–g, j–l) or IMR90 (h, i) cells were used; data shown are means ± s.d.; two-tailed t-test, n = 3 biologically independent experiments (d–l); images in b, c are representative of two independent experiments. Data in d–f, j–l and Fig. 1b were from large experimental sets sharing IgG controls. Data in h, i were from large experimental sets sharing IgG controls.
