OF WORMS AND MEN - AN EVOLUTIONARY PERSPECTIVE ON THE FIBROBLAST GROWTH-FACTOR (FGF) AND FGF RECEPTOR FAMILIES

FGFs (fibroblast growth factors) play major roles in a number of devel opmental processes. Recent studies of several human disorders, and con current analysis of gene knock-out and properties of the corresponding recombinant proteins have shown that FGFs and their receptors are pro minently involved in the development of the skeletal system in mammals . We have compared the sequences of the nine known mammalian FGFs, FGF s from other vertebrates, and three additional sequences that we extra cted from existing databases: two human FGF sequences that we tentativ ely designated FGF10 and FGF11, and an FGF sequence from Coenorhabditi s elegans. Similarly, we have compared the sequences of the four FGF r eceptor paralogs found in chordates with four non-chordate FGF recepto rs, including one recently identified in C. elegans. The comparison of FGF and FGF receptor sequences in vertebrates and nonvertebrates show s that the FGF and FGF receptor families have evolved through phases o f gene duplications, one of which may have coincided with the emergenc e of vertebrates, in relation with their new system of body scaffold.