Cover Story:
The process of inducing the germ cell lineage from pluripotent stem cells, referred to as in vitro gametogenesis, aids in comprehending the mechanisms involved in germ cell differentiation and offers an alternative source of gametes for reproduction. Shirasawa et al. have developed a novel method for robust induction of primordial germ cell-like cells (PGCLCs) from newly established bovine embryonic stem (bES) cells (Shirasawa et al.: Efficient derivation of embryonic stem cells and primordial germ cell-like cells in cattle, pp. 82–95). After a 24-hour culture with bone morphogenetic protein 4 (BMP4), followed by a three-dimensional culture with BMP4 and chemicals modulating WNT signaling, bES cells exhibited positive expression for a set of primordial germ cell (PGC) markers, including PRDM1/BLIMP1, TFAP2C, and SOX17. These outcomes are anticipated to have practical implications for the development of stem cell-based reproductive technologies in cattle.