Primary Cultures of Spermatogonia and Testis Cells.

Spermatogonial stem cells (SSCs) maintain adult spermatogenesis in mammals by undergoing self-renewal and differentiation into spermatozoa. In order to study the biology of SSCs as related to spermatogenesis, an in vitro, long-term expansion system of SSCs constitutes an ideal tool. In this chapter, we describe a robust culture system for mouse and rat SSCs in vitro. In the presence of GDNF, GFRα1, and bFGF, SSCs maintained on STO feeder layers with serum-free medium continuously proliferate for over 6 months. Complete spermatogenesis in infertile recipient mice can be attained following transplantation of the cultured mouse and rat SSCs. Using the in vitro SSC culture systems, elucidation of stem cell biology can be advanced that significantly advances our understanding of spermatogenesis and male fertility.