(A, B) In situ hybridization of antrum using Shh and Ihh specific probes. (C-F) X-gal stained antral sections from E16.5 Ptch1LacZ/+, Gli1LacZ/+, and Gli2LacZ/+ antrum. (F) Cross section of the forming pyloric border in a Gli1 LacZ/+ mouse reveals a drastic difference in active Hh signaling between the stomach (S, left) and intestine (I, right); Py = pylorus. Arrowheads = Gli1 positive serosal cells. Bars = 100μm.