Apoptosis or programmed cell death is a process that occurs during development of the nervous system. The aim of this study was to observe the patterns of apoptosis that occur during embryonic development of the retina from the stage S16 at birth, by light and electron miscoscopia. Turtle embryonic retinas were used for the study. Our data show that the first signs of apoptosis begins at stage S16 in the inner nuclear layer and reaches maximum density both in the inner nuclear layer and the ganglion cell layer in S20 until they practically disappear at the time of birth. Furthermore, apoptosis follows a gradient center-periphery.
KEY WORDS: Trachemys scripta elegans; Apoptosis; Retina; Turtle.