Fig. 6. Cell number changes across the width of the definitive endoderm. (A) Plot of the average definitive endoderm cell number in wild-type (gray) and chato mutant (red) mice. Cells were counted in sections of the definitive endoderm stained with Fast Red at medial levels along the anterior-posterior axis (see Fig. 4). Error bars indicate s.d. (B) Average number of cells ±s.d. The total number of sections counted for each condition is indicated (# sections); na, not assayed. ^***P<0.0001.