Transplanted primary neonatal myoblasts can give rise to functional satellite cells as identified using the Myf5(nlacZ/+) mouse

Myoblast transplantation is a potential therapeutic approach for the geneti c modification of host skeletal muscle tissue. To be considered an effectiv e, long-lived method of delivery, however, it is essential that at least a proportion of the transplanted cells also retain their proliferative potent ial. We sought to investigate whether transplanted neonatal myoblasts can c ontribute to the satellite cell compartment of adult skeletal muscle by usi ng the Myf5(nlacZ/+) mouse. The Myf5(nlacZ/+) mouse has nlacZ targeted to t he Myf5 locus resulting in beta -galactosidase activity in quiescent satell ite cells. Following transplantation, beta -galactosidase-labelled nuclei w ere detected in host muscles, showing that donor cells had been incorporate d. Significantly, beta -galactosidase-positive, and therefore donor-derived , satellite cells were detected When placed in culture, beta -galactosidase marked myogenic cells emanated from the parent fibre. These observations d emonstrate that cell transplantation not only results in the incorporation of donor nuclei into the host muscle syncytia, but also that the donor cell s can become functional satellite cells. The Myf5(nlacZ/+) mouse therefore provides a novel and specific marker for determining the contribution of tr ansplanted cells to the satellite cell pool.