Fig. 3: Chrne RNA produced in postsynaptic nuclei is confined to the NMJ region.

A Representative image of FISH for Ttn (green) and Chrne (red) RNA in an extrasynaptic region of an isolated EDL myofiber. Scale bars: 2 µm. B Representative image of FISH for Ttn (green) and Chrne (red) RNA in the NMJ of an isolated EDL myofiber. Scale bars: 2 µm. C Quantification of RNA density for Ttn and Chrne RNAs in extrasynaptic (blue) and NMJ regions (red) of myofibers. Extrasynaptic regions: n = 5 myofibers; NMJ regions: n = 8 myofibers. *p < 0.05, **p < 10⁻⁴. Two-sided Mann–Whitney U test. Dotted line indicates lower limit of detection (LLOD). D Tubulin IF in NMJ region of an isolated myofiber. Scale bars: 2 µm. E IF/FISH co-labeling of Ttn RNA (red), tubulin protein (microtubules, green), and telethonin protein (Z-disks, blue) at the NMJ of an isolated myofiber. Scale bar: 2 µm. F IF/FISH co-labeling of Chrne RNA (red), tubulin protein (microtubules, green), and telethonin protein (Z-disks, blue) at the NMJ of an isolated myofiber. Scale bar: 2 µm. G Large field of view image of IF/FISH co-labeling of Chrne RNA (red), tubulin protein (microtubules, green), and telethonin protein (Z-disks, blue). * indicates Chrne RNAs in the extrasynaptic myofiber neighboring the NMJ. † indicates extrasynaptic nuclei containing Chrne mRNAs. ^ indicates NMJ region containing high concentration of Chrne RNA. Scale bar: 10 µm.