L'ONTOGENESI DEL SISTEMA OLFATTIVO E VISIVO DEI VERTEBRATI

The area of the retina grows progressively until stage 31, which represents the metamorphic climax. Highly significant increases are recorded at the stadium just 28 and 31. A similar trend can be observed for the number of total cells that make up the retina, but they, having achieved a significant increase in stage 28, growth arrest. This is not surprising, since growth of the retina is also related to the counterpart of fiber, of course, continue to increase until stage 31. As expected, the strong mitotic activity in the early stages of development and suffers a decrease up to the stage 21 and then increased to 28, after which suffers a terminal decline after metamorphosis in which mitotic figures become more sporadic. The minimum mitotic stage 21 does not correspond to a slowdown in growth in the number of cells, but the significant increase in the number of cells observed at the stage 28, is concordant with the second increase in mitotic index. The development of apoptosis in two waves does not leave visible signs on the growth of the retina, even if this first wave coincides with a minimum mitotic apoptosis, as evidenced also based on the graph of PARP-1 fragmentation. The second wave of apoptosis, however, shall determine, in conjunction with the fall of mitotic activity, a drastic decrease in cells of the retina. In Coturnix coturnix in the early stages of eye development studies covered an embryo after 4 days of incubation, where you look at the outline of the eye