Figure 1
From: Collagen XXV promotes myoblast fusion during myogenic differentiation and muscle formation
Col25a1 expression is required for muscle development in mice. (A) Immunofluorescence analysis of myosin positive myofibers on transverse sections of forelimbs from wild-type (WT) and Col25a1−/− E14.5 embryos. Total nuclei were stained with Hoechst. Scale bar: 30 µm. edc: extensor digitorum communis; s: supinator; ecrb: extensor carpi radialis brevis; ecrl: extensor carpi radialis longus. (B) Quantitation of myosin positive myofibers on transverse sections of forelimbs from E14.5 WT and Col25a1−/− embryos. (C) Distribution of myosin positive myofiber cross-sectional areas (n = 3 animals of each genotype). *P < 0.05; **P < 0.01 vs WT. (D) Myosin immunofluorescence on forelimb longitudinal muscles from WT and Col25a1−/− E14.5 embryos (n = 3). Multinucleated myofibers were observed in WT sections. Col25a1−/− myofibers were myosin positive but shorter. Scale bar: 50 µm. Arrows indicate bulges. bbl: biceps brachii long head. (E) E12.5 forelimbs (n = 4) were immunostained with an antibody directed against the embryonic isoform of MyHC (emb-MyHC). Col25a1−/− myoblasts fusion seems to be delayed. High magnification of emb-MyHC staining (right) corresponds to area in white box from the left panel. Scale bar: 50 µm. Arrows indicate breaks between aligned myofibers.
