Loss of <i>T</i>. <i>brucei</i> RNase H1 results in increased transcription of silent VSGs.

A. The left panel provides a simplified diagram of VSG expression sites (ES) used to generate a protective surface coat in the bloodstream T. brucei cells used in this study; only telomere-proximal VSGs (coloured boxes, numbered) from a selection of ES are shown, and the single ES being actively transcribed (encoding VSG221, pink) is denoted by an arrow extending from the promoter (flag). The right panel shows a graph of VSG RNA levels (corresponding to the ES diagram, and determined by RT-qPCR) in TbRH1 null mutants (Tbrh1-/- cells), plotted as fold-change relative to levels of the cognate VSG RNA in wild type cells (WT427 1.2); VSG 221 is in bold to indicate it is in the active ES of wild type cells, and data are presented as mean +/- SD for three independent experiments; * P B. A graph depicting the number of VSG genes that display >1.5-fold increase in RNA abundance (determined by RNA-seq, and normalised to gene length and total number of reads) in Tbrh1-/- cells relative to WT; the total number is sub-categorised depending on whether the VSGs have been localised to the bloodstream ES (BES), are intact genes in the subtelomeric arrays (array), are in mini-chromosomes (MC), are pseudogenes (pseudo), or are in the ES transcribed in the metacyclic life cycle stage (MES). C. Plots of normalised RNA-seq read depth abundance (y-axes) relative to CDS position (x-axes) for a selection of the above VSGs; VSG identity numbers are from [16].