Xenotransplantation assessment: morphometric study of human spermatogonial stem cells in recipient mouse testes

The purpose of this study was (i) To establish in vitro propagation of human spermatogonial stem cells (hSSCs) from small testicular biopsies to obtain a high number of cells; (ii) to evaluate the presence of functional hSSCs in culture system by RT-PCR using DAZL, α6-Integrin, β1-Integrin genes; and (iii) to evaluate the effects of cell concentration on successful xenotransplantation of hSSCs in mice testis. Donor hSSCs were obtained from men with maturation arrest of spermatogenesis duration 1 year ago. These cells were propagated in DMEM containing 1 ng ml(-1) bFGF (basic fibroblast grow factor) and 1500 U ml LIF (leucaemia inhibitory factor) for 5 weeks. Different concentrations of hSSCs transplanted into seminiferous tubules of busulfan-treated immunodeficient mice and analysed up to 8 weeks after transplantation. The results showed that expression of DAZL and α6-Integrin mRNA was increased as well as the colony formation of SSCs in vtro culture during 5 weeks. Proliferation occurred about 4 weeks after transplantation, but meiotic differentiation was not observed in recipient testis after 8 weeks. The difference in donor cells concentration had effect on homing spermatogenesis in recipient testis. Homologous transplantation of proliferated SSCs to seminiferous tubules of that patient individually may allow successful differentiation of transplanted cells.