Fig. 2. Comparative histology of P15 wild-type and Hoxa5^–/– gut specimens. Hematoxylin and Eosin stained sections of stomach (A,B), duodenum (C,D), jejunum (E,F), ileum (G,H), and proximal (I,J) and distal colon (K,L) from wild-type (A,C,E,G,I,K) and Hoxa5^–/– (B,D,F,H,J,L) mice revealed a thinning of the gastric epithelium (B) and a reduction in villi length in the proximal colon (J) in Hoxa5^–/– mutants. In both structures, the submucosa was hypertrophied. The duodenum (D), the jejunum (F), the ileum (H) and the distal colon (L) appeared morphologically normal. e, epithelium; m, muscular layer; s, submucosa. Scale bar: 100 µm.