Hematopoietic progenitors and stem cells in murine muscle

We investigated hematopoietic capabilities of murine skeletal muscle using methylcellulose culture and transplantation into lethally irradiated mice. Muscle mononuclear cells (MNC) contained colony-forming cells and long-term engrafting cells. Studies using chimeric mice indicated a bone marrow orig in of the hematopoietic cells in the muscle. We then separated muscle MNC b y FACS sorting into Ly-5-positive cells and Ly-5-negative cells and analyze d their hematopoietic capability in vitro and in vivo. The hematopoietic pr ogenitors and stem cells were present only in the Ly-5-positive fraction. ( C) 2001 Academic Press.