THE LOSS OF GAP JUNCTIONAL CELL-TO-CELL COMMUNICATION IS COUPLED WITHDEDIFFERENTIATION OF RETINAL PIGMENTED EPITHELIAL-CELLS IN THE COURSEOF TRANSDIFFERENTIATION INTO THE LENS

Retinal pigmented epithelial cells (PECs) of the chick embryo can be c ultured as a monolayer of melanized hexagonal cells. Modifications of the culture condition make the cells lose most of the phenotypes and f urther transdifferentiate into lentoid bodies within a few weeks. Ultr astructural observations showed that PECs and the lentoids have gap ju nctions with distinct morphology. Diffusion of a fluorescent dye confi rmed the presence of gap junctions in both phenotypes. However, cells in the intermediate stage of transdifferentiation, which show neither the phenotype of the PEC nor that of the lentoid and are called dediff erentiated PECs here, have almost no gap junction structure. We propos e the possibility that the dedifferentiation of PECs and the loss of c ell-to-cell communication are tightly coupled events. This cell cultur e system is a suitable material for further studying this relationship by cellular and molecular approaches.