FIBROBLAST GROWTH-FACTOR RECEPTORS AND REGENERATION OF THE EYE LENS

If the eye lens of the adult newt, Notophthalmus viridescens, is remov ed, a new lens will regenerate and only from the dorsal, not the ventr al, iris, The source, pigmented epithelial cells, would normally no lo nger divide, but upon lentectomy they do re-enter the cell cycle and f orm lens. The cause for this capability is unknown, but the mitogenic Fibroblast Growth Factors and their receptors may be involved. We have demonstrated that FGF receptors are present and operative in lens reg eneration, since receptor-directed mitotoxins inhibit regeneration; he terogeneity and differential density in FGF-binding and receptor local ization in iris sectors is also present. We propose that the spatial d istribution of FGF receptors, especially the amphibian homolog of FGFR -3, is important in initiation of regeneration of eye lens. (C) 1997 W iley-Liss,Inc.