IN VITRO DEVELOPMENT OF REGENERATING LENS

The development in vitro of the regenerating lens at successive time intervals after lens removal was studied in the adult newt Triturus viridescens. Regenerates were cultured using an agar substrate in which a synthetic medium with serum supplement was incorporated. Explants were incubated at 25°C, 5% CO2, and 85% relatively humidity, and cultured for 5, 10, and 15 days. Regeneration stages I to II, in which nuclear activation and depigmentation are starting to occur, continue to extrude their pigment granules and give rise to a population of completely depigmented cells. After depigmentation has occurred in vivo in some cells of the dorsal iris (stages III to IV), a depigmented cell population is produced capable of limited proliferation but incapable of lens fiber differentiation. When cell elongation has occurred in the depigmented cells of the inner wall of the regenerating lens (stages V and onward), explants are capable of developing lens fibers in vitro. These results are discussed and related to the available information on RNA and protein synthesis in the lens regenerating system. © 1969.