Embryo-derived stem cell lines respectively express lineage-associated markers. (A) Brief schematic representation of mouse pre-implantation development and origin of lineage-derived stem cells. Embryonic stem (ES), trophectoderm stem (TS) and extra-embryonic endoderm (XEN) can be derived from the inner cell mass (yellow), trophectoderm (blue) and primitive endoderm (red) of mouse blastocysts. (B) Reverse transcription polymerase chain reaction expression analysis of ESOS25, TSB1 and XENIM8A1 cells lines. RNA was isolated and cDNA prepared from all three embryo-derived stem cell lines cells and analysed using primers for Oct4, Nanog, Sox2, Fgf4, Rex1, Cdx2, Eomes, Esrrb, Hand1, Gata4, Gata6, Foxa2, Hnf4 and Gapdh as a loading control. +/- indicates presence or absence of reverse transcriptase; H2O, water control.