The interaction of epithelial Ihha and mesenchymal Fgf10 in zebrafish esophageal and swimbladder development

► The zebrafish Indian Hedgehog a (Ihha) is expressed in the intestinal epithelium. ► It acts in parallel with Shh in development of smooth muscles and neurons in the gut. ► Ihha controls development of swimbladder in zebrafish. ► In esophagus and swimbladder Ihha and Fgf10 form a positive signaling feedback loop.