Growth and cytodifferentiation of embryonic chick lens epithelial cells in vitro

Abstract

Cytodifferentiation, mitotic activity, tritiated thymidine binding and cell migration were studied in 297 6-day embryonic chick lens epithelia explanted into defined medium alone (UM) or into defined medium supplemented with serum (SM). Lens epithelial cells explanted into UM alone did not undergo significant cytodifferentiation nor cellular proliferation. Cells explanted directly into SM rapidly differentiated into short prospective lens fibers and failed to show significant proliferative activity. If the lens epithelial cells were precultured for 12 to 24 h in UM before transfer to SM, the cells rapidly lost their capacity to differentiate under these experimental conditions. As the ability to form short fibers was lost, the explanted cells showed greatly enhanced mitotic and migratory activity when stimulated by the addition of serum containing medium. The possibility is discussed that the rapidly lost capacity of lens epithelial cells to form fibers is due to the loss or inactivation of a cell component or components involved in the synthesis of tissue-specific proteins, and, being unable to differentiate under these experimental conditions, the cells are stimulated to proliferate and to migrate by the addition of serum.