Developmental roles of platelet-derived growth factors

Platelet-derived growth factor (PDGF) was originally identified in platelet s and in serum as a mitogen for fibroblasts, smooth muscle cells (SMC) and glia cells in culture. PDGF has since expanded to a family of dimers of at least four gene products, whose biological actions are mediated through two receptor tyrosine kinases, PDGFRs, The present review summarizes and discu sses the biological functions of PDGFs and PDGFRs in developmental processe s, mainly as revealed through genetic analysis in mice. Such studies have d emonstrated multiple critical roles of PDGFs and PDGFRs in embryonic and po stnatal development. PDGFs seem to act upon specific populations of progeni tor cells that give rise to several different cell types with distinct func tions in a variety of developmental processes, Analogies are seen between t he cell functions and the developmental processes controlled by PDGFs, This suggests that ancestral PDGF and PDGFR expression patterns and functions m ay have been iterated in related sets of morphogenetic processes in the cou rse of evolution. (C) 2001 John Wiley & Sons, Inc.