[Immunolocalization of fodrin in the retina of vertebrates]

Fodrin, a member of the spectrin family, is abundantly found in brain and lens. Based on its often observed peripheral cellular distribution, it is generally believed that fodrin - like other spectrins - participates in the linkage of membrane components to cytoskeletal elements providing their anchorage to distinct, highly specialized membrane regions. To investigate the role of fodrin in the vertebrate (amphibian) retina, we have produced polyclonal antibodies in rabbits against fodrin purified from veal lens. The distribution of fodrin within the retina of Xenopus and Rana has been assessed by indirect immunofluorescence on cryostat sections and on isolated epithelial cells. In general, the staining pattern reflects the structural and functional polarity of the retinal layers. Fodrin is found in axons, dendrites and synapses of neurons, in the inner segment of photoreceptors, and as a peripheral ring of the epithelial cells. This study represents the first step of an investigation on the development and differentiation of specific, fodrin-containing membrane regions in the amphibian retina.