Developmental expression patterns of the signaling adapters FRS-2 and FRS-3 during early embryogenesis

Two fibroblast growth factor (FGF) receptor substrates (FRS2 and FRS3) are involved in downstream signaling from activated FGF receptors and neurotrop hin-activated Trk receptors. Despite the importance of signaling from these factors in embryogenesis, FRS2 and FRS3 expression patterns during develop ment are unknown. In this study we characterize the expression of FRS3 and FRS3 from E7 to parturition and in adult murine tissues. Both are first det ected in whole E8.5 CD1 mouse embryos. FRS2 is detected as early as E7 in t he developing syncytiotrophoblast, later in the neural tube (NT) and in man y adult and fetal tissues. FRS3 is more restricted in location than FRS2 (f etal NT, heart, stomach, liver and some adult tissues), and is expressed pr edominantly in the ventricular layer of the developing NT and brains of mur ine embryos. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.