QUANTITATIVE STUDIES ON STIMULATION OF MITOSIS AND DNA SYNTHESIS IN CULTURED RABBIT OCULAR LENS

Rabbit lenses cultured in a serum-containing medium undergo a series of characteristic changes in epithelial mitotic activity. During the first 9-hr mitosis practically ceases. It subsequently resumes, reaches a peak at 20 hr, and then once again decreases to a low level. The above changes, all of which occur in the periphery of the epithelial layer, herald the initiation of a pronounced stimulation of DNA synthesis (thymidine incorporation) in the central region. At 44 hr the number of cells in mitosis in the central region increases enormously. The S plus G-2 phases of the cell cycle for these central cells last approximately 11-15 hr.