[Differentiation of pluripotent stem cells into male germ cells: An update]

Pluripotent stem cells (PSCs), including embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), have the potential of differentiating into all types of adult cells. Today, mature functional sperm can be derived from mouse PSCs in vitro, and meanwhile primordial germ cells (PGCs) and meiotic prophase sperm cells can be generated from human ESCs/iPSCs (hESCs/hiPSCs). It is proposed that non-genetic azoospermia might be cured if functional sperm could be obtained from human PSCs (hPSCs) in vitro. It is also possible that healthy functional sperm could be derived from the patient with genetic factor-induced azoospermia by combining iPSCs and gene editing technology. IPSC-derived functional sperm have a higher clinical value for the avoidance of the sperm source and the issue of medical ethics. This article summarizes recent advances in the differentiation of PSCs into male germ cells in vitro, aiming to provide some reference for the treatment of male infertility with PSCs.