Establishment in Culture of Mouse Expanded Potential Stem Cells

The zygote and blastomeres of a cleavage stage mouse embryo have the capacity to differentiate to all lineages in the embryo proper and extraembryonic tissues and are considered totipotent. Mouse ESCs can differentiate to embryonic lineages but have restricted potential to trophoblasts. We report here that cultures of a new type of stem cells with expanded potential (EPSCs) can be established from in vitro cultured mouse preimplantation embryos and individual blastomeres, from directly converting mouse ESCs, or from genetically reprogramming somatic cells. EPSCs differentiate to trophoblasts in vitro, and a single EPSC contributes in chimeras to both extraembryonic lineages including the placenta trophoblasts and the embryo proper. Molecular analyses reveal that EPSCs express core pluripotency factors similar to ESCs, but have enriched signature of preimplantation blastomeres. The data described here suggest that similar cell lines from other mammalian species might also be established in culture and stably maintained.