Phase contrast images of C57BL/10 MSCs (A-E) and mdx MSCs (F-I). Passage 0 (A, F), passage 9 (B, G), passage 19 (C, H), passage 25 (D, I), and passage 40 (E). Round cells (A-I: thin black arrows). Spindle-shaped cells (A-I: arrowheads). Cells in Fig. G were more spindle-shaped than those in Fig. B. Cells in Fig. H to Fig. C showed the same result. Mesh and net formation was observed between the cells in Fig. I (pentagram). Scale bar, 200 μm.