Evolution of the Fgf and Fgfr gene families.
Fibroblast growth factors (Fgfs) and Fgf receptors (Fgfrs) comprise a signaling system that is conserved throughout metazoan evolution. Twenty-two Fgfs and four Fgfrs have been identified in humans and mice. During evolution, the Fgf family appears to have expanded in two phases. In the first phase, during early metazoan evolution, Fgfs expanded from two or three to six genes by gene duplication. In the second phase, during the evolution of early vertebrates, the Fgf family expanded by two large-scale gen(om)e duplications. By contrast, the Fgfr family has expanded only in the second phase. However, the acquisition of alternative splicing by Fgfrs has increased their functional diversity. The mechanisms that regulate alternative splicing have been conserved since the divergences of echinoderms and vertebrates. The expansion of the Fgf and Fgfr gene families has enabled this signaling system to acquire functional diversity and, therefore, an almost ubiquitous involvement in developmental and physiological processes.
Itoh
Nobuyuki
N
Department of Genetic Biochemistry, Kyoto University Graduate School of Pharmaceutical Sciences, Yoshida-Shimoadachi, Sakyo, Kyoto 606-8501, Japan. itohnobu@pharm.kyoto-u.ac.jp
Ornitz
David M
DM
D000818:Animals; D002874:Chromosome Mapping; D019143:Evolution, Molecular; D005346:Fibroblast Growth Factors / Q000235:genetics* / Q000502:physiology; D008040:Genetic Linkage; D006801:Humans; D005810:Multigene Family; D017468:Receptors, Fibroblast Growth Factor / Q000235:genetics* / Q000502:physiology; D014714:Vertebrates / Q000235:genetics
D017468:Receptors, Fibroblast Growth Factor; D005346:Fibroblast Growth Factors