(A) At birth, p0, Gli1 expressing cells are found in villus cores and in close contact with the presumptive crypt epithelium (arrows). (B) At p10, the developing MM contains Ptch1 positive cells (arrowhead). (C-E) Gli1 positive cells of the MM and villus cores (blue nuclei, arrowheads) are positive for αSMA (red) and desmin (green), identifying them as SM cells. (F-H) Gli1, Gli2 and Ptch1 expressing cells (arrows) are in close contact with the tips of the forming crypts at P10. Bars: 50μm for A and B; 20μm for C-H.