mRNA in situ hybridization exhibits unbalanced nuclear/cytoplasmic dystrophin transcript repartition in Duchenne myogenic cells and skeletal muscle biopsies.

To gain insight on dystrophin (DMD) gene transcription dynamics and spatial localization, we assayed the DMD mRNA amount and defined its compartmentalization in myoblasts, myotubes, and skeletal muscle biopsies of Duchenne muscular dystrophy (DMD) patients. Using droplet digital PCR, Real-time PCR, and RNAscope in situ hybridization, we showed that the DMD transcript amount is extremely reduced in both DMD patients' cells and muscle biopsies and that mutation-related differences occur. We also found that, compared to controls, DMD transcript is dramatically reduced in the cytoplasm, as up to 90% of it is localized in nuclei, preferentially at the perinuclear region.