Endogenous nuclease activity in chick embryo lens cells.

The temporal and spatial sequence of nuclear disappearance during the terminal differentiation of lens fiber cells could be due to an impairment of the DNA repair pathways or to the appearance of an active DNA degradation process. The results presented here favor the second hypothesis. A single-stranded DNA nuclease activity and a double-stranded DNA nuclease activity have been found in chick embryo fiber cells. Moreover, there is a good correspondence between the variations of the nuclease activity and the stages of differentiation of the different samples analyzed.