Serum- and Feeder-Free Culture of Mouse Germline Stem Cells

Spermatogonial stem cells (SSCs) undergo self-renewal divisions to support spermatogenesis Although several in vitro SSC culture systems have been developed, these systems include serum or fibroblast feeders, which complicate SSC self renewal analyses Here, we developed a serum- and feeder-free culture system for long-term propagation of SSCs In addition to the SSC self-renewal factors, including glial cell line derived neurotrophic factor, supplementation with fetuin and lipid-associated molecules was required to drive SSC proliferation in vitro Cultured cells proliferated for at least 6 mo at a rate comparable to that of serum supplemented cultured cells However, germline potential was reduced under serum- and feeder-free conditions, as indicated by a lower SSC frequency after germ cell transplantation Nevertheless, the cultured cells completed spermatogenesis and produced offspring following spermatogo mal transplantation into seminiferous tubules of infertile mice This culture system provides a basic platform for understanding the regulation of SSC fate commitment in vitro and for improving SSC culture medium