Expression patterns of focal adhesion associated proteins in the developing retina

Authors

  • Ming Li,

    1. Department of Zoology and Genetics, Iowa State University, Ames, Iowa
    2. Interdepartmental Graduate Programs in Neuroscience and Molecular, Cellular, and Developmental Biology (MCDB), Iowa State University, Ames, Iowa
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  • Donald S. Sakaguchi

    Corresponding author
    1. Department of Zoology and Genetics, Iowa State University, Ames, Iowa
    2. Interdepartmental Graduate Programs in Neuroscience and Molecular, Cellular, and Developmental Biology (MCDB), Iowa State University, Ames, Iowa
    3. Department of Biomedical Sciences, Iowa State University, Ames, Iowa
    • Department of Zoology and Genetics and Neuroscience Program, 339 Science II, Iowa State University, Ames, IA 50011
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Abstract

Adhesive interactions between integrin receptors and the extracellular matrix (ECM) are intimately involved in regulating development of a variety of tissues within the organism. In the present study, we have investigated the relationships between β1 integrin receptors and focal adhesion associated proteins during eye development. We used specific antibodies to examine the distribution of β1 integrin ECM receptors and the cytoplasmic focal adhesion associated proteins, talin, vinculin, and paxillin in the developing Xenopus retina. Immunoblot analysis confirmed antibody specificity and indicated that β1 integrins, talin, vinculin, and paxillin were expressed in developing retina and in the retinal-derived Xenopus XR1 glial cell line. Triple-labeling immunocytochemistry revealed that talin, vinculin, paxillin, and phosphotyrosine proteins colocalized with β1 integrins at focal adhesions located at the termini of F-actin filaments in XR1 cells. In the retina, these focal adhesion proteins exhibited developmentally regulated expression patterns during eye morphogenesis. In the embryonic retina, immunoreactivities for focal adhesion proteins were expressed in neuroepithelial cells, and immunoreactivity was especially strong at the interface between the optic vesicle and overlying ectoderm. At later stages, these proteins were expressed throughout all retinal layers with higher levels of expression observed in the plexiform layers, optic fiber layer, and in the region of the inner and outer limiting membrane. Strong immunoreactivities for β1 integrin, paxillin, and phosphotyrosine were expressed in the radially oriented Müller glial cells at later stages of development. These results suggest that focal adhesion-associated proteins are involved in integrin-mediated adhesion and signaling and are likely to be essential in regulating retinal morphogenesis. © 2002 Wiley-Liss, Inc.

Ancillary