Establishment of a simple, efficient, and scalable method to generate oocyte-like cells in vitro

Understanding the molecular basis of oocyte identity and function is essential not only for basic biology but also for clinical applications, as it is closely linked to female infertility. However, technical challenges remain in advancing this understanding, mainly due to the difficulty of obtaining a sufficient number of oocytes. In this study, we established a two-dimensional culture method that efficiently generates oocyte-like cells, referred to as mini-oocytes, from mouse embryonic stem cells. This method requires minimal labor and leverages a transcription factor-mediated approach for oocyte-like cell generation. Our analyses revealed significant similarities between in vitro-derived mini-oocytes and in vivo oocytes. Furthermore, we demonstrated the utility of mini-oocytes for investigating oocyte-specific molecular features through a small-scale knockout screen targeting the subcortical maternal complex. Given the simplicity, efficiency, and scalability of the mini-oocyte induction method, it offers a practical alternative for conducting experiments that are otherwise challenging with in vivo oocytes. Overall design: Total RNA-seq were performed using mini-oocytes.