Novel cell lines from mouse epiblast share defining features with human embryonic stem cells

The application of human embryonic stem (ES) cells has an inherent reliance on understanding the starting cell population. Human ES cells differ from mouse ES cells and the specific embryonic origin of both cell types is unclear. Previous work suggested that mouse ES cells could only be obtained from the embryo prior to implantation in the uterus. Here we show that cell lines can be derived from the epiblast, a tissue of the post-implantation embryo that generates the embryo proper. These cells, which we refer to as EpiSCs (post-implantation epiblast-derived stem cells), express transcription factors known to regulate pluripotency, maintain their genomic integrity, and robustly differentiate into the major somatic cell types as well as primordial germ cells (PGCs). The post-ES cell lines are distinct from mouse ES cells in their epigenetic state and the signals controlling their differentiation. Furthermore, post-ES and human ES cells share patterns of gene expression and signalling responses that normally function in the epiblast. These results show that epiblast cells can be maintained as stable cell lines and interrogated to understand how pluripotent cells generate distinct fates during early development. This SuperSeries is composed of the SubSeries listed below.