REGULATION OF LENS REGENERATION BY FIBROBLAST-GROWTH-FACTOR RECEPTOR-1

Lens regeneration in vivo is restricted to some urodeles only. After r emoval of the lens, this remarkable event is initiated from the dorsal iris. The pigmented epithelial cells from the dorsal iris dedifferent iate and subsequently transdifferentiate to form the regenerating lens . This property of the dorsal iris implies specific regulation along t he dorsal-ventral axis. To date, no known genes are known to be specif ically expressed in the dedifferentiating cells and to be involved in lens regeneration In this paper, we show that FGFR-1 expression and fu nction is correlated with the process of lens regeneration from the do rsal iris. Following lentectomy, FGFR-1 protein is specifically presen t in the dedifferentiating pigment epithelial cells in the dorsal iris , but is absent from the ventral iris. Subsequently, FGFR-1 protein is present throughout the process of lens regeneration and fiber differe ntiation. Furthermore, we show that an FGFR-1-specific inhibitor is ab le to inhibit the process of transdifferentiation and lens regeneratio n. In this sense, FGFR-1 can be regarded as the first known lens regen eration-associated factor. Dev. Dyn. 1998;213:140-146. (C) 1998 Wiley- Liss, Inc.