Fig. 5. Nodal-expressing ES cells were tightly regulated and differentiated into definitive endoderm and mesoderm in vivo. Teratoma formation in each condition. (A) graft weight, ^*P<0.001 compared with wild-type ES cells transplants or Nodal on/on grafts. (B) Representative images of grafts and kidney. Nodal on/off grafts clearly had smaller tumors 3 weeks after engraftment in comparison to wild-type or Nodal on/on grafts. (C) The expression of the pluripotent marker, Oct4, in the grafts. (D) RT-PCR analysis showing gene expression in graft including the transcriptional targets of Nodal, and the mature definitive endoderm, mesoderm, and neuroectoderm. (E) Immunofluorescence images of Foxa2, proSftpC, albumin, Pdx1, glucagon and IFABP in Nodal on/off grafts were obtained by confocal microscopy. The original magnification was 400x; bars, 50 µm.