Spermatogonial Stem Cells and Spermatogenesis

This chapter reviews the development of the spermatogonial stem cell (SSC) field from the late 1800s to 2014 and envisions the fundamental and practical advances that the field will experience in the coming decades. We describe the current models of SSCs and spermatogenic lineage development in rodents, nonhuman primates, and humans to identify features that are conserved through evolution as well as species-specific differences. We describe experimental tools used to study SSCs and spermatogenic lineage development and discuss how data generated with those tools should be interpreted. We discuss the current knowledge about the molecular mechanisms that regulate SSC function and, more importantly, the knowledge gaps that will be the focus of future investigations. Finally, we describe how SSCs and the SSC transplantation technique can be exploited to produce transgenic animals, develop biopharmaceuticals, and treat male infertility.