Fig. 2. Formation of adipocytes in mouse myofiber cultures. (A-D) Representative images of myofiber-derived cultures co-stained with DAPI (blue) and oil-red-O (red). (A) Multilocular cells (indicated with arrows) in a non-myogenic area within a 10-day-old culture. (B) Multi-, pauci- and unilocular cells (indicated by the upper right, middle and lower left arrows, respectively) in a non-myogenic area of a 3-week-old culture. (C,D) Myoblasts and myotubes exhibiting minimal staining with oil-red-O in 10- and 21-day-old cultures; myoblasts are indicated with arrows in panel C and a myotube is indicated with an arrowhead in panel D; a multilocular cell present in panel D is indicated with an arrow. Bar, 20 µm. (E) Graph depicting the number of fiber cultures containing adipogenic cells accumulating during a 6-week period.