Cell population growth during the formation of the chick eye lens

The eye lens, a radially symmetrical and autonomously growing organ, contai ns dividing cells in the epithelium while fibre cells do not divide. Betwee n day 7 and day 15 of chick embryogenesis, the annular pad extending from t he peripheral epithelium is formed which acts as a reservoir of proto-diffe rentiated fibres that are then transferred to the fibre area. Around the op tical axis, a wave of apoptosis is generated in terminally differentiated f ibre cell nuclei. We have determined cell numbers in the epithelium, the an nular pad and fibre compartments and the data fit a logistic model the best , indicating a saturating growth. The growth rates for various lens compart ments change with time.