Fig. 6. Rathke’s pouch is smaller in Lhx4^–/– mice owing to cell death at E12.5. Tunnel assay at E12.5 (A-D) and at E14.5 (E-H) demonstrated that only a few cells are dying (arrows) in the pituitary of wild-type (A) and Prop1^df/df (B) mice. However, numerous dying cells were detected in Rathke’s pouch at E12.5 in Lhx4^–/– (C) and Prop1^df/dfLhx4^–/– (D) mice. At E14.5 no cell death was detected in any of the genotypes: wild type (E), Prop1^df/df (F), Lhx4^–/– (G) and Prop1^df/dfLhx4^–/– (H).