Fig. 6: (GGGGCC)_n ability to aggregate in its RNA form and to interact with TDP-43 RRM1-2.

a RNA (GGGGCC)_n aggregates in a G4-dependent fashion, r(GGGGCC)₆ NMM staining experiment—r(GGGGCC)₆ was annealed under mG4-forming conditions (see methods). It was then subjected to NMM staining prior to acquisition. The image is split to show the brightfield channel (on the right) and the NMM fluorescence channel (on the left). 10 µm scalebar. b r(GGGGCC)₆ NMM photo-oxidation experiment—Upon laser excitation the NMM dye bound to the mG4s photo-oxidises the guanine in the quadruplex, leading to the disassembly of the structure (see methods). The region of interest (ROI) highlighted in the figure was irradiated for 1 min and the second image was subsequently acquired, showing condensate disassembly due to photo-oxidation. 10 µm scalebar. Micrographs from panels a and b are representative of n = 2 respective independent replicates. c Brightfield and NMM-stained imaging of TDP-43 RRM1–2 and (GGGGCC)₁₁—(GGGGCC)₁₁ was annealed under mG4-forming conditions (1–300 µM) and then incubated with 10 µM TDP-43 RRM1–2, revealing a synergist aggregation effect between the (GGGGCC)n repeats and TDP-43. 100 µm scalebar. Micrographs in panel c are representative of 3 technical replicates and n = 2 independent biological replicates.