Expression patterns of Wnt genes in mouse gut development

Wnt signaling regulates cell fate decisions and cell proliferation during development and in adult tissues in both invertebrates and vertebrates. Here we describe the identification of Wnt genes, Wnt2a, 4, 5a, 5b, 6 and 11, expressed in mouse embryonic gut development. Each of these gents exhibits a characteristic and regional-specific expression pattern along the anterior-posterior axis of the digestive tube between embryonic day (E) 12.5 and 16.5 of embryonic development. The expression of Wnt5a is confined to the mesenchymal compartment, while expression of Wnt4 is found both in the intestinal epithelium and the mesenteric anlage. Wnt 11 is expressed in the epithelium of esophagus and colon, but also in mesenchymal cells of the stomach. Wnt5b and Wnt6 exhibit restricted expression in the epithelium of the esophagus. A characteristic regionalized expression pattern is observed in the developing stomach. Wnt5a is expressed in the mesenchymal layer of the prospective gland region but becomes restricted to the: tip of the gland region by E14.5. Wnt 11 is highly expressed at the gastroesophageal junctions, while Wnt4 is found in the epithelium lining the pyloric region of the stomach but not in the epithelium of the prospective gland region. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.