Fig. 4. Reduction of HS epitopes in NDST-1^–/– primary muscle cell culture. Immunofluorescence staining for (a,c,e,g) HS-epitope AO4B05 and (b,d,f,h) acetylcholine receptor clusters in (a,b,e,f) wildtype, (c,d) NDST-1^–/– and (g,h) NDST-2^–/– primary muscle culture after three days of differentiation. HS staining is absent in NDST-1^–/–derived myotubes and mononuclear cells. In contrast, NDST-2^–/– cultures are not affected. Myotubes in all cultures show spontaneous acetylcholine receptors clusters (arrows; n=5). Bar, 50 µm.