Spred2 expression during mouse development.

SPREDs (Sprouty-related proteins with Ena/Vasodilator-stimulated phosphoprotein homology-1 domain) are known membrane-associated modulators of receptor tyrosine kinases by inhibiting the mitogen-activated protein kinase (MAPK) signaling pathway. Although Spred2(-/-) mice exhibit dwarfism and increase of early haematopoiesis, the precise expression and role of SPRED2 in mouse development remains unknown. Here, we demonstrate a detailed Spred2 expression pattern during mouse development using X-Gal stainings from samples of a gene-trapped Spred2 mouse line. In early stages, Spred2 was highly expressed in ectodermal and mesodermal tissues, and later on in developing neural tissue, heart, lung, intestine, urogenital tract, and limbs. Strikingly, we observed that Spred2 was mainly expressed at leading edges of further outgrowing structures and in folds of newly forming grooves. Therefore, SPRED2 is likely involved in the regulation of dynamic developmental processes. These new data provide valuable information for further studies regarding the still enigmatic physiological SPRED functions during mouse development.