Arrest of WNT/β-catenin signaling enables the transition from pluripotent to differentiated germ cells in mouse ovaries

Significance In the mammalian ovary, primordial germ cells maintain a genomic program associated with pluripotency until they stop proliferating, move toward oogenesis, and enter meiosis. The molecular mechanisms that enable primordial germ cells to exit pluripotency and enter meiosis in a timely manner are unclear, and their identification represents a major challenge in reproductive biology because the fertility of each individual depends on this. Evidence that cessation of germ cell proliferation is a cell-autonomous event, unrelated to the number of cell divisions, led to a search for an intrinsic timing mechanism that has long remained elusive. We describe here that WNT/β-catenin signaling regulates this timing and coordinates the transition from pluripotent to gametogenesis-competent germ cells.