Functions and regulations of fibroblast growth factor signaling during embryonic development.

Fibroblast growth factors (FGF) are secreted molecules which function through the activation of specific tyrosine kinases receptors, the FGF receptors that transduce the signal by activating different pathways including the Ras/MAP kinase and the phospholipase-C gamma pathways. FGFs are involved in the regulation of many developmental processes including patterning, morphogenesis, differentiation, cell proliferation or migration. Such a diverse set of activities requires a tight control of the transduction signal which is achieved through the induction of different feedback inhibitors such as the Sproutys, Sef and MAP kinase phosphatase 3 which are responsible for the attenuation of FGF signals, limiting FGF activities in time and space.