Barrier activity requires the RNA polymerase III complex.

<p>A. Chromatin IP analysis of cen1 for enrichment of Sfc6 (TFIIIC) and Rpc130 (Pol III). The X-axis represents 1.5 kb of cen1 imr including tDNA^Ala (green) and nearby tDNA^Glu (white). Centromere specific primers are listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0001099#s4" target="_blank">Materials and Methods</a>. Error bars represent SEM. B . Real time RT-PCR analysis of centromeric <i>ura4⁺</i> transcription normalized to endogenous <i>ura4⁺</i> transcription in strains containing wild-type or mutant barriers (Left). Indicated strains were analyzed by chromatin IP for Sfc6 (Middle, dark gray) and Rpc130 (Right, light gray) enrichment. Error bars represent SEM.