Fig. 7. Effect of Sox17 deficiency on ExE differentiation. (A) The temporal expression pattern of ExE markers in wild-type (WT) and Sox17^–/– (KO) EBs. RNA from EBs grown without LIF for the indicated periods was subjected to qRT-PCR. The expression levels relative to the maximal levels are shown as the mean±s.d. values of two independent experiments. (B) Toluidine-blue staining of EBs grown without LIF for 3 or 9 days. Arrows, PrE-like cells; arrowheads, PE-like cells. Bars, 10 µm. (C) Immunostaining for COUP-TF1 and Gata4 in EBs grown for 4, 9 or 12 days. Bars, 50 µm.