Background: Some research studies provided evidence for the differentiation capacity of
adult stem cells (ASCs) into germ cells (GCs). Since the generation of GCs from stem cells (SCs) has
been proposed as a potential way for treatment of infertility, many research groups have begun their
creative studies on generation of new GCs both in vitro and in vivo, and utilized different ASC types
such as bone marrow mesenchymal stem cells (BM-MSCs), skin stem cells, pancreatic stem cells, and
adipose tissue MSCs. Despite many interesting reports with promising results, an obvious problem in
the research projects was the functionality of the produced GCs.
Objective: In this paper, we have reviewed the results of almost all previously published reports on
derivation of male and female GCs from ASCs to provide a better insight into this field of research.
Results: The most evaluated papers have shown that ASCs from various tissues can differentiate into
GCs but rarely were the produced GCs functional and could form fertile gametes neither in vitro, nor
in vivo (after transplantation into the gonads).
Conclusion: There are still so many unknown issues about gametogenesis. Perhaps making alterations
in treatment methods and utilizing creative techniques like tissue engineering and gene targeting help
to achieve a standard method of in vitro GC production from ASCs.