SER3 repression is primarily dependent on the Paf1 and Ctr9 subunits. (A) Representative Northern analysis of SER3, SRG1, and SCR1 (loading control) RNA levels in wild-type (FY5), paf1Δ (KY1700), ctr9Δ (KY2170), leo1Δ (KY1805), cdc73Δ (KY1706), and rtf1Δ (KY1703) strains. (B) Quantitation of results from a minimum of seven biological replicates. The values shown are the mean SER3 (black) and SRG1 (gray) transcript levels, normalized to the SCR1 loading control and made relative to the wild-type strains. Error bars indicate standard errors of the means, and asterisks indicate statistical significance compared to the wild type (*, P < 0.05; **, P < 0.01). (C) Representative Northern analysis of SER3, SRG1, and SCR1 (loading control) RNA levels. The wild-type strain (YJ1087) was transformed with a control plasmid (pRS416). The paf1Δ strain (YJ786) was transformed with either pRS416 (−PAF1) or pRS316-HA-PAF1 (+PAF1). The ctr9Δ (YJ759) strain was transformed with either pRS416 (−CTR9) or pAP10 (+CTR9). (D) Quantitation of results from a minimum of three biological replicates. The values shown are the mean SER3 (black) and SRG1 (gray) transcript levels, normalized to the SCR1 loading control and made relative to the wild-type strains. Error bars indicate standard errors of the means, and asterisks indicate statistical significance compared to the wild type (*, P < 0.05; **, P < 0.01).