Cre/Lox-β-galactosidase cell transplantation and muscle injury resulted in β-gal/LacZ positive mononuclear cells.

<p>Three weeks after cell transplantation into MDX/SCID mice, many (β-gal/LacZ)+/dystrophin+ myofibers were observed (<b>A</b>, <b>B</b>). β-gal/LacZ staining and immunofluorescent Pax7/dystrophin staining are shown here; arrows indicate (β-gal/LacZ)+/dystrophin+ myofibers which are the result of the fusion of Cre-Lox myocytes, and arrowheads indicate (β-gal/LacZ)−/dystrophin− host myofiber (<b>A</b>, <b>B</b>). Three weeks after transplantation and four days after muscle injury in SCID mice, some (β-gal/LacZ)+ mononuclear cells were observed in the injured muscle (<b>E–G</b>), but not in the control non-injured muscle (<b>C</b>, <b>D</b>). Results of β-gal/LacZ staining and HE staining are shown here; arrows indicate (β-gal/LacZ)+ myofibers, and arrowheads indicate (β-gal/LacZ)+ mononuclear cells (<b>C–G</b>). Some of the (β-gal/LacZ)+ mononuclear cells were shown to be Pax7+ (<b>H–K</b>). Images H–J are of the same location, and result of β-gal/LacZ staining and immunofluorescent Pax7/dystrophin staining are shown here (<b>H–J</b>); arrows indicate β-gal+/Pax7+ mononuclear cells, and arrowheads indicate β-gal+ myofibers (<b>H–J</b>). Fluorescent co-staining of β-gal and Pax7 are also shown (K); arrowheads indicate β-gal+/Pax7+ mononuclear cells, and arrows indicate Pax7+ cells. Statistical quantification of the results is also shown (<b>L</b>).