October 1, 2021

Review: Mammalian in vitro gametogenesis

In vitro gametogenesis

In vitro gametogenesis. IVG aims to recreate germ cell development in vitro using PSCs, including iPSCs from somatic cells. Human IVG realization requires further efforts and will create new opportunities in reproductive biology research and medicine. ART, assisted reproductive technologies.

A review paper by ASHBi Director/PI Dr Mitinori Saitou was published online in Science on October 1, 2021.


Germ cells differentiate into sexually dimorphic gametes, oocytes, and spermatozoa, which unite to form new individuals. Accordingly, germ cell development entails intricate regulations of genome functions for genetic and epigenetic inheritance. The past decade has seen considerable advances in in vitro gametogenesis (IVG), which aims to recreate germ cell development from pluripotent stem cells (PSCs) in culture. Mouse PSCs can be induced into functional oocytes and spermatozoa, whereas human PSCs can be induced into early oocytes and prospermatogonia, promoting mechanistic understanding of mammalian germ cell development. The prospect for inducing human gametes with appropriate functions has been heightened, and such advances will create possibilities in reproductive medicine, including modeling infertility to explore remedies. The use of IVG-derived gametes for human reproduction will require careful legal and ethical discussions.

Paper Information

Mitinori Saitou, Katsuhiko Hayashi, “Mammalian in vitro gametogenesis” (2021), Science, DOI: