Fig. 5. Localisation of endogenous MURF2 relative to titin Z-disk and I-band epitopes. At different stages of differentiation, double immunofluorescence experiments were performed with anti-MURF2 (green), and either anti-titin I-band (A,B) or anti-titin Z-disk (C-E) antibodies (red). At 24 hours of differentiation (A) MURF2 did not decorate the stress fibre like structures revealed with titin I antibody. After 120 hours of differentiation (B), MURF2 and I-band titin epitopes showed occasional transversal colocalisation (arrowhead) near mature cross-striated regions of the myofibril (arrow). In young myotubes (24 hours of differentiation) Z-disk titin can align along MURF2 positive microtubules (C,D). When sarcomeres started to be organised (E), structures with MURF2 punctate staining (arrowhead) co-aligned with maturing Z-disk titin (arrow).