Lens development. V. Histological analysis of the mechanism of lens reconstitution from implants of lens epithelium

A piece of five-day embryonic lens epithelium was implanted in place of the right lens in each of 89 five-day-old chick embryos. The steps in the reconstitution of whole lenses from these grafts were identified by histologic analysis. Immediately following the implantation of the lens epithelium large numbers of cells came out of the anticapsular surface. Many of these died. Some of the survivors adhered in groups to the anticapsular surface of the implant. The cut edges of the implant became reflected so that the capsular surface was bent convexly. The reflected epithelium joined the groups of cells adhering to the anticapsular surface of the implant to form a flattened vesicle. The Golgi apparatuses of these cells lay at the anticapsular poles. The basal (capsular) poles of the cells always came to lie outermost regardless of the initial orientation of the implant. In time the vesicle filled the orifice of the eye cup and the reconstituted lens vesicle became invested externally by a continuous sheet of lens capsule. The cells in the wall of the vesicle that lay toward the vitreous body elongated to form lens fibers. A lens equatorial zone appeared facing the edge of the eye cup regardless of the orientation that had been given the implant initially. Thus, all of the reconstituted lenses were properly oriented in the eye.