Fig. 4. Detection of GFP⁺ muscle fibres and possible satellite cells in neonatal chimeras. H-E staining (A,C,E) and GFP fluorescence (B,D,F) of CTX-treated TA muscles of neonatal chimeras. (A,B) Neonatal bone marrow chimera; (C-F) neonatal fetal liver cell chimera; (G,H) a single GFP⁺ fibre with peripheral nucleus in a intact (CTX-untreated) neonatal bone marrow chimera; (I) detection of a GFP⁺ mononuclear cell beneath the laminin layer (rabbit anti-laminin plus rhodamine-conjugated goat anti-rabbit IgG) (neonatal bone marrow chimera); (J-O) desminstained explanted fibres (J,L,M,O) were examined for GFP fluorescence (J,K,M,N). A GFP⁺ cell attaching to a single fibre was stained with desmin (arrowheads of (L) and (O)). (P) Positive control of explanted muscle cells from GFP-Tg mouse (mixed color of desmin and GFP); (Q-T) are muscle sections of the secondary mdx/scid recipient. Single cell suspension from intact (CTX-untreated) muscles of neonatal bone marrow chimera was obtained and injected into CTX-treated TA muscle of the mdx/scid recipient. GFP⁺ fibres were observed (arrowheads of (R) and (T)). Bar, 50 µm (A-H and Q-T).