3 research outputs found
DNA synthesis in the embryonic chick lens epithelium is arrested after experimental lens rotation
Using autoradiographic technique, we have
studicd DNA synthesis in normal embryonic chick lens
epitheliuni and after experimental lens rotation.
Analysis of the autoradiograms clearly demonstrates
that when the lens priniordium was rotated 180". so that
lens epithelium was placed facing the interior of the
optic cup. the lens epithelial cells completely stop DNA
synthesis. This fact suggests that some retinal and vitieal
factors are responsible for differentiation and replicative
capacity of the lens epithelial cells
Regional adaptation of Muller cells in the chick retina. A Golgi and electron microscopical study
We report the morphological differences of Müller cells in relation to their topography, using the Golgi method. Müller cells in the central retina are long and slender, with numerous inner prolongations. In the peripheral retina, the morphology of the Müller cells adapts to the reduced thickness of the retina1 layers. In this zone, they are short and have thick inner prolongations which end in a large foot in the internal limiting membrane. In the optic disc margin, Müller cells have a particular morphology characterized by thick, arched prolongations that in general form a glial network between the retina and optic nerve. The ultrastructure of these cells is also described. The results are discussed with respect to the nature of Müller cells
Effect of ethanol on the cerebellar cortex of the chick embryo
The effect of ethanol on the cerebellar cortex of chick embryos was studied in semi-thin sections of material prepared for electron microscopy. The embryos were injected with ethanol on the 3rd or 6th day of incubation and observed until days 13, 15, 17 and 21 of development. A decrease was seen in the number of germinal cells generated, together with defects in neuronal migration and the existence of a lower quantity of cells due to a generalised process of cell death. At the same time, a progressive neuronal degeneration was observed until the 15th day of incubation, the tissue recovering progressively on days 17 and 21. On the other hand, the embryos treated with ethanol on the 3rd day were less affected than those injected on the 6th day