Movie 4

Generation of new muscle fibers by cell fusion. col1a2^Kaede fish was injured at 3 dpf and imaged from 29 hpi onwards. A Kaede⁺ MPC (arrows) near the injury site elongated at 34 hpi (white arrowheads), formed protrusions at 39 hpi, and fused with a neighboring muscle fiber at 40 hpi. The newly formed muscle fiber can be identified by the weak Kaede expression throughout the muscle fiber and the strong Kaede expression in the nucleus (yellow arrowheads). Representative snapshots are shown in Figure 6D. Scale bar: 50 μm.