Muscle regeneration during the late differentiation stage.

<p>Two limbs are shown in A and C. Dashed lines indicate the amputation plane. White arrows indicate the regenerating muscle, and asterisks indicate the parental muscle. (B) Enlarged image of the boxed area in A; arrowhead indicates a gap between the regenerating and parental muscles. (C) A limb in a late stage of regeneration; the late stage is indicated by the diameter of the regenerating limb being approximately the same as that of the proximal region. D, E, F, and G show enlarged images of the boxed areas in C. The muscle-fiber alignment and ColIV localization here (D) are not as clearly organized as in the proximal region (E); this indicates that the regenerating muscle is still not mature. Arrowheads in F and G indicate the connection between the regenerating and parental muscles. Scale bars = 200 μm in A, B, F, and G; 400 μm in C; 100 μm in D and E.