Fig. 1: VEX2 is allele-selective.

a–e VEX2^myc chromatin immunoprecipitation followed by deep sequencing (ChIP-Seq). VEX2 enrichment across the genome is expressed as ChIP versus input fold change (FC). a The circos plot shows VEX2-enrichment (purple) across the T. brucei core genome (11 megabase chromosomes), and bloodstream and metacyclic VSG-ESs. The inner track shows data for a no myc-tag control (wild-type; grey). The ‘active’ and the ‘silent’ expression sites depicted in (b) are highlighted. The SL-array on chromosome 9 is also highlighted, black line. b VEX2-enrichment at the active VSG-ES and one ‘silent’ VSG-ES. c, d VEX2 (purple) and VEX1 (orange) enrichment traces at the active VSG-ES (c) and at the Spliced Leader-arrays⁵¹ (d) are overlayed. e The violin plots show VEX2-enrichment across VSG or ESAG CDSs within bloodstream VSG-ESs. a–e Bin size 0.5 kb; values are averages of two biological replicates. f DNA-FISH combined with immunofluorescence followed by super-resolution microscopy. Cells where VEX2 was endogenously tagged with 12xmyc at the C-terminus (orange) were co-stained with biotin and digoxigenin-labelled DNA probes targeting the 50-bp repeats (all VSG-ESs, green) and SL-arrays (magenta). DNA was stained with DAPI (grey). The images were acquired using a Zeiss LSM880 Airyscan, are representative (80 G1 cells were imaged across two independent experiments), and correspond to maximum-intensity 3D projections; 0.1 μm stacks.