Restoration of spermatogenesis after transplantation of c-Kit positive testicular cells in the fowl.

Transplantation of male germ line cells into sterilized recipients has been used in mammals for conventional breeding as well as for transgenesis. We have previously adapted this approach for the domestic chicken and we present now an improvement of the germ cell transplantation technique by using an enriched subpopulation of c-Kit-positive spermatogonia as donor cells. Dispersed c-Kit positive testicular cells from 16 to 17 week-old pubertal donors were transplanted by injection directly into the testes of recipient males sterilized by repeated gamma irradiation. We describe the repopulation of the recipient's testes with c-Kit positive donor testicular cells, which resulted in the production of functional heterologous spermatozoa. Using manual semen collection, the first sperm production in the recipient males was observed about nine weeks after the transplantation. The full reproduction cycle was accomplished by artificial insemination of hens and hatching of chickens.