Fig. 1.

Experimental set-up and methods of analysis. ROSA26 mice were lethally irradiated and transplanted with either GFP⁺ WBM or bone marrow SP cells. Seven weeks after transplantation, recipient muscles were damaged with intramuscular cardiotoxin injections. Five and 14 days later, bone marrow and cardiotoxin-damaged muscles were harvested for various analyses (shaded boxes). Recipient bone marrow was analyzed for lineage reconstitution by transplanted cells via FACS. FACS was also used to analyze mononuclear muscle cells for donor cell contribution and for the markers CD45 and Sca-1. Cells from this muscle analysis were sorted based on GFP and CD45 expression, and transferred to slides via cytospin where they were stained for myogenic markers Desmin, MyoD and Pax7. Whole TA muscles were also frozen, sectioned for immunohistochemistry, stained for β-galactosidase and assayed for engraftment of donor-derived cells. Overall, at least seven rounds of irradiation/transplantation were carried out with at least three mice.