[Formation and reorganization of the early photoreception area in the eyes of sturgeon embryos and prelarvae. Radioautographic study].

A study of the development of eye retina in sturgeons (Acipenser güldenstädti and A. stellatus) by means of autoradiography has shown that during embryogenesis the cells of the high light sensitivity region complete the cycle of proliferation prior to the stage 29, what corresponds to the completion of proliferation of the retina cells in anurans and mammals, rather than at the stage 33, as was considered previously on the basis of the light microscopy morphological studies of differentiation. The cells of definitive retina begin to complete the cycle of proliferation at the stage 35 and the mass completion occurs at the stage 37. Some parameters of mitotic cycle were determined in the cells of definitive retina at the stages 34 and 37 and they proved to be similar with the corresponding parameters of the retina cells in anurans. The time of G2 period equals 2.5 hrs, that of S period 14 hrs and the whole mitotic cycle lasts 21.5 hrs. The transformation of the retina of high light sensitivity region in the definitive retina proceeds, mainly, by means of migration of the cells in this zone from the zone of intensive proliferation surrounding the high light sensitivity region. This transformation proceeds by means of morphological rearrangement of metamorphosis type.