Figure 5. HBE is required for Nodal expression in ESCs but not in EpiSCs.

(A) Depiction of the two Nodal alleles (WT on top and recombinant at the bottom) before and after Cre recombination. (B–C″) Expression of Oct4 (B, C) and YFP (B′, C′) in recombinant ESCs before (B–B″) and after (C–C″) Cre recombination. (D–E″) Expression of Oct4 (D, E) and YFP (D′, E′) in recombinant EpiSCs, 6 d after transfection with a control plasmid (D–D″) or with Cre recombinase (E–E″). Single confocal sections. n is the number of YFP-positive colonies. Scale bar, 25 µm.