Extended Data Fig. 5: Effects of treatment with DRB on splicing-factor and transcriptional condensates.

a, Representative images exhibiting overlap or lack of overlap between immunofluorescence of SRSF2 and DNA FISH of Trim28 in mouse ES cells treated with DMSO for 2 h, DRB for 2 h, or DRB for 2 h followed by a 2-h DRB washout. b, Representative images exhibiting overlap between immunofluorescence of MED1 and DNA FISH of Trim28 in mouse ES cells treated with DMSO for 2 h, DRB for 2 h, or DRB for 2 h followed by a 2-h DRB washout. c, Representative images exhibiting overlap between immunofluorescence of Pol II and DNA FISH of Nanog or Trim28 in mouse ES cells treated with DMSO for 2 h, DRB for 2 h, or DRB for 2 h followed by a 2-h DRB washout. d, Fraction of overlap of FISH foci with immunofluorescence puncta in cells treated with DRB or DRB followed by washout, relative to cells treated with DMSO. The asterisk above the DRB-treated bar indicates *P < 0.05 from a two-tailed χ² test comparing the number of overlapping and non-overlapping FISH spots in the DMSO versus DRB condition. The asterisk over the washout bar indicates *P < 0.05 from a two-tailed χ² test comparing the DRB versus washout condition. The splicing factors that we tested showed a significantly decreased, or trended towards a decreased, overlap with FISH spots in the DRB condition compared to DMSO, whereas MED1 and Pol II exhibited limited changes (see Methods).