A The ratio of CTD S2-P relative to Rpb3 at 3' ORF regions was analyzed by ChIP using anti-S2-P and anti-Rpb3 antibodies. The error bars represent the SD from triplicate experiments. Data information: Asterisks represent statistically significant differences between WT and ulp2Δ using a two-tailed Student's t test (*, P <0.05; **, P <0.01). 