We demonstrate that Sprouty genes 1, 2 and 4 are expressed in several developing organs of the craniofacial area and trunk, including the brain, cochlea, nasal organs, teeth, salivary gland, lungs, digestive tract, kidneys and limb buds. In organs such as the semicircular canal, Rathke's pouch, nasal organs, the follicle of vibrissae and teeth, Sprouty1 and Sprouty2 are expressed in the epithelium and Sprouty4 in the mesenchyme or neuronal tissue, while in the lung Sprouties1, 2and4 are all expressed mainly in the epithelial tissue. In the kidney, Sprouty1 is prominent in the ureteric bud whereas Sprouty2 and 4 are expressed in both the ureteric bud and the kidney mesenchyme and glomeruli deriving from it. The expression profiles suggest roles for these Sprouties in the epithelial-mesenchymal interactions that govern organogenesis.
