Figure 2.

Nuclear foci of CUG^exp RNA and MBNL1 protein are dispersed in muscles treated with siCAG. (a) Fluorescence in situ hybridization (FISH) shows reduction of CUG^exp foci (red) in nuclei (blue) in isolated flexor digitorum brevis (FDB) muscle fibers. Muscle was taken 7 days after electroporation of siCAG or saline. Inset shows magnification of selected nuclei. Nuclei are counterstained blue using 4,6 diamino-2-phenylindole dihydrochloride (DAPI). (b) Combined FISH for CUG^exp RNA (red) and immunofluorescence for MBNL1 protein (green) in transverse sections of tibialis anterior muscle from human skeletal actin—long repeat mice. Muscle was taken 7 days after electroporation of siCAG or saline. The CUG^exp foci are dispersed and the MBNL1 distribution is more diffuse in siCAG-treated muscle. Nuclei are counterstained blue (DAPI). (c) Immunofluorescence of isolated FDB muscle fibers shows redistribution of MBNL1 (green) from punctate to diffuse localization in the nucleus (blue), 7 days after electroporation of siCAG.Scale bars = 5 µm. Objective: 100× Plan Apo, 1.4 NA oil.