Summary
Nudging germ cell precursors into functionally mature oocytes and spermatozoa is a key aspect of in vitro gametogenesis and a major challenge in the study of reproductive biology. This process is biologically complex, not only determined by the developmental competency of the germ cell itself but also critically dependent on the gonadal niche. On page 298 of this issue, Yoshino et al. (1) report the in vitro derivation of fetal ovarian somatic cellтАУlike cells (FOSLCs) from murine pluripotent embryonic stem cells, using a stepwise, directed differentiation strategy to reconstruct in vivo differentiation. These cells sufficiently supported the development of germ cell precursors into functional oocytes that went on to produce viable, fertile mice. The ability to generate and assemble the critical components necessary for oogenesis in the laboratory provides a model system to study the later events of oogenesis, and this may have implications for assisted reproductive technologies.
