Mono-allelic epigenetic regulation of bi-directional polycistronic transcription initiation by RNA Polymerase II in Trypanosoma brucei.

In vitro selection of Bloodstream form T. brucei with the trypanosome lytci factor (TLF) led to generation of parasites resistant to TLF. We not show that resistance is due to silencing Pol II transcription initiaiton at promoter for the gene array that includes the TLF receptor gene HpHbR. Reversable transcriptional silencing of the HpHbR gene array and the adjacent gene array, correlates with DNA base J modification of the shared promoter region. We demonstrate that epigenetic mechanisms exist to regulate gene expression via Pol II transcription initiation of polycitronic gene arrays in a monoallelic fashion. The role of PP1-1 in regulating transcription termination was investigated using RNAi ablation in T. brucei cell lines. We used 6 RNA seq libraries to determine gene expression changes following the loss of PP1-1. As a control we used 6 RNA seq libraries to determine changes following the loss of PP1-7.