Figure 2.

Chronic Replication Stress Induces Stochastic Instability of Bu-1a Expression that Is Largely Dependent on the +3.5 G4 Motif

(A) Example flow cytometry plots for Bu-1a expression in wild-type and BU-1^ΔG4 cells, before and after 7 days culture in 150 μM HU, are shown.

(B) Potentiation of HU-induced instability of Bu-1a expression by the +3.5 G4, but not the −3.0 G4. Wild-type cells (i), BU-1^Δ+3.5G4 cells (ii), and BU-1^Δ-3.0G4 cells (iii) are shown.

(C) Determinants of BU-1 instability induced by the +3.5 G4 motif. (i) The +3.5 G4 motif was knocked back into BU-1^ΔG4 cells. (ii) Knockin of the +3.5 G4 motif mutated to prevent intramolecular G4 formation (Schiavone et al., 2014). (iii) Knockin of the +3.5 G4 motif inverted so that the G4 forms on the lagging-strand template.