Immunochemical analysis of water-soluble antigens of chick retina in the course of embryogenesis.

Water-soluble antigens of chick retina were investigated using rabbit antisera to total extract and to individual electrophoretic fractions of retinal extract by methods of immunoelectrophoresis and Ouchterlony precipitation test. In the retina of the adult chick six serum and eleven tissue antigens were demonstrated. The tissue antigens of the retina comprised one organ-specific antigen and ten inter-organ antigens which were characterized by nonuniform distribution in tissues and organs of adult chick. Three antigens out of these were found only in tissues of the eye (retina, iris) and in the brain--inter-organ antigens of 'narrow' specificity. The ohter seven inter-organ antigens were found in tissues of brain and eye, as well as in various tissues and organs of hens--inter-organ antigens of 'broad' specificity. A high degree of antigen similarity between retina and iris was observed. Anti-retina sera in chick lens could detect only inter-organ antigens of 'broad' specificity. In the course of embryogenesis the first to appear in the developing retina were inter-organ antigens of 'broad' specificity (on 3rd day of incubation). Formation of antigens of this group was completed by the 9th day of incubation. On the contrary, inter-organ antigens of 'narrow' specificity appeared later, in the period of histogenesis of retina (from 5 to 18 days of incubation). The organ-specific antigen of retina was found by 7th day of incubation. One of the inter-organ retinal antigens of'narrow' specificity (retina-iris-brain) appeared in the developing chick brain at the same time as in retina--on 10th-11th day of incubation. Using the indirect immunofluorescence antibody technique this antigen was identified in the cytoplasm of retinal cells and brain neurones, but was not detected in the nerve fibres.