Fig. 6.

Gaps between transcribing Pol I complexes are more frequently observed in ctr9Δ cells than in WT. Position of 5′ ends of gaps (gap start sites) is shown on an rRNA gene normalized in length. Also indicated is the portion of gap start sites with polymerase pileups (see Materials and Methods). The absence of gap start sites in the 3′ quarter of the gene is caused by the minimum length requirement (¼ gene length) for gaps to be included in the analysis.