Spermatogonial stem cells: Progress and prospects

Area of Science:

• Reproductive Biology
• Stem Cell Science
• Developmental Biology

Background:

• Spermatogonial stem cells (SSCs) are crucial for continuous sperm production in males.
• The transplantation of SSCs has been a key method to demonstrate their functional identity and self-renewal capacity.
• Significant advancements have been made in understanding SSCs over the past two decades.

Purpose of the Study:

• To review the major advancements in spermatogonial stem cell research over the last 20 years.
• To highlight key findings in SSC kinetics, hierarchy, culture, and in vitro induction.
• To assess the current status and future prospects of SSCs in reproductive medicine.

Main Methods:

• Review of key research findings and technical developments in SSC transplantation and culture.
• Analysis of studies on SSC self-renewal, proliferation, and differentiation.
• Examination of in vitro germ cell induction from pluripotent stem cells.

Main Results:

• Successful SSC transplantation in mice confirmed their functional identity.
• Development of methods for SSC self-renewal, proliferation, and testis tissue organ culture.
• In vitro induction of germ cells from embryonic and induced pluripotent stem cells has been achieved.
• New hypotheses on SSC kinetics and testicular hierarchy have emerged.

Conclusions:

• Twenty years of research have substantially advanced the understanding of spermatogonial stem cells.
• Despite significant progress, numerous challenges remain for the clinical application of SSCs in reproductive medicine.
• Further research is needed to overcome existing hurdles for therapeutic use.