Extended Data Fig. 5: Close association of TLs with splicing factors.

Splicing factors (SON) and components of exon-junction complexes EIF4A3 and RBM8A (Y14), are either co-stained with RNAPII Ser2P (the two top rows) or visualized together with TLs in immuno-FISH (the rest of the rows). Note that signals of TLs and splicing factors colocalize only partly. The myotube nucleus is tetraploid and thus exhibits 4 Ttn RNA signals. Images are partial projections of either 0.6 µm (for immunostaining) or 0.9 µm (for immuno-FISH). Scale bars: 2 µm, in close-ups, 1 µm. Data represent 3 independent experiments.