Serial CTD truncations led to progressive steady state transcriptional defects.

<p>Expression microarrays were normalized using spiked in controls to determine global changes in mRNA levels. As no such changes were detected, the expression profiles were normalized to total mRNA levels. Differentially expressed genes were determined by p value <0.01 and fold change >1.7 compared to wild type. (A) Heatmap of genes with significantly increased (top) or decreased (bottom) mRNA levels in the <i>rpb1-CTD11</i> mutant. Groups A, B and C approximately outline subsets of genes whose expression were decreased when the CTD was truncated to 13, 12 or 11 repeats respectively. Yellow indicates genes with increased mRNA levels and blue indicates genes with decreased levels. (B) Scatterplot of profile paired correlations in gene expression and genetic interaction. Boxplot of transcriptional frequency (C) and mRNA half-life (D) showing significant differences in half-life (p value 4.54e-14) and transcriptional frequency (p value 0.0131) between genes with increased or decreased expression in the <i>rpb1-CTD11</i> mutant. Outliers are not shown. (E) Differences in enriched transcription factors between genes with increased or decreased mRNA levels.