Abstract
Monoclonal antibody 5E10 binds to Muller cells in the chick retina and radial glia in the optic tectum. Biochemical and immunohistochemical experiments indicate that the 5E10 antigen is related to, but may not be identical to, filamin, a high-molecular-weight, actin-binding protein. Developmental studies show that the 5E10 antigen is present in all neuroepithelial cells very early in development, but disappears by about Embryonic Day 10. These results suggest that neurons developmentally regulate not only the type of intermediate filament proteins they express, switching from vimentin to neurofilaments, but also the type of actin-binding proteins.