Fig. 2

Nucleoli appeared to be unaffected by expression of DUX4-FL. a–b” Staining for endogenously expressed DUX4-FL (red) and nucleolin (green) in three nuclei within a single myotube. In these nuclei, DUX4-FL expression did not appear to affect nucleolar structure, and there was little or no overlap of punctate staining for DUX4-FL with nucleolin. In all panels, dotted lines indicate approximate borders of individual nuclei. c–d” Staining for endogenously expressed DUX4-FL (red) and nucleolin (green) in several nuclei within a single myotube. Exogenous DUX4-FL expression, whether predominantly punctate (c) or predominantly uniform (d) also did not appear to affect nucleolar structure, and there was also little or no overlap of exogenous DUX4-FL and nucleolin staining. e – e” When expressed in myotubes, the non-cytotoxic, short DUX-S isoform was uniformly distributed in nuclei and did not appear to affect nucleolar structure. Bar in A = 20 μm for rows a–d and 15 μm for row e