Human pluripotent stem cells cradled by a mouse ovarian environment—a sort of living “dish”—differentiated into states that brought the cells close to becoming mature oocytes. The cells, which were evaluated over the course of a months-long experiment, progressed epigenetically toward reproductive competence, suggesting that induced pluripotent stem cells, given the right culture conditions, can become human egg cells.

The encouraging findings emerged from a study conducted by scientists based at Kyoto University. These scientists, led by Mitinori Saitou, M.D., Ph.D., professor, anatomy and cell biology, Kyoto University, detailed their work in a paper (“ Generation of human oogonia from induced pluripotent stem cells in vitro ”) that appeared recently in the journal Science . According to this paper, the scientists not only derived primordial germ cell-like cells (hPGCLCs) from human pluripotent stem cells (hPSCs), they found a way to help the hPGCLCs differentiate, show oocyte-specific characteristics, and pass through …