How are pluripotent cells captured in culture?

Abstract

In mice, three pluripotent stem cell lines have been established from different stage of developing embryo, which are embryonic stem (ES) cell, post-implantation epiblast stem cell (EpiSC), and embryonic germ (EG) cell. ES cell and EG cell share many common features including factor requirement, colony morphology, and gene expression pattern. On the other hand, EpiSC needs different external signal inputs, exhibits flattened colony morphology, and a different set of gene expression patterns. In addition, the germ line competency of EpiSCs is still unclear. To distinguish the differences between them, they are defined by the words "naïve" and "primed" pluripotent cells, respectively. This article introduces how pluripotent stem cell lines are established in culture, and how much those cells in vitro are similar or relevant to their in vivo origin and the knowledge about transcription factors to support this state.

Keywords: EG cells; ES cell; EpiSC; Epiblast; Pluripotency.

Figure 1

Pluripotent cells in culture and their origin in embryos a E4.5 mouse embryo. a’ Mouse embryonic stem cell cultured in 2i and LIF on a gelatin‐coated plate. b E5.5 mouse embryo. b’ Mouse EpiSC cultured in activin and bFGF on fibronectin‐coated plate. c E8.5 mouse embryo. c’ Mouse EG cells cultured in 2i and LIF with feeder cells. Cells in blue in (a, b) show the pluripotent epiblast and in c show the location of PGC cells at this stage. Red cells in (a, b) are extra‐embryonic endoderm cells. Scale bar in a, b is 50 µm and a’–c’ is 100 µm