The sevenless+ protein is expressed apically in cell membranes of developing Drosophila retina; it is not restricted to cell R7

Cell. 1987 Oct 9;51(1):151-8. doi: 10.1016/0092-8674(87)90020-1.


In the sevenless (sev) mutants of Drosophila, a single cell type, photoreceptor R7, does not develop. We made monoclonal antibody against a sev+-beta-galactosidase fusion protein, and used it to determine the ultrastructural localization of the sev+ protein in the larval eye disc. The protein is expressed on the apical surface of the developing retina. It is not restricted to cell R7; it is expressed in all the presumptive photoreceptor cells, cone cells, and possibly others. The protein localizes to the cell membranes of the apical tips and their microvilli, away from the bulk of the cell-cell contacts. Possible mechanisms for generating the specificity of the sev phenotype are discussed in light of these results.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antibodies, Monoclonal
  • Cell Differentiation
  • Cell Membrane / metabolism
  • Drosophila melanogaster / genetics
  • Drosophila melanogaster / metabolism*
  • Electrophoresis, Polyacrylamide Gel
  • Epithelium / metabolism
  • Eye / metabolism
  • Eye / ultrastructure*
  • Eye Proteins / genetics
  • Eye Proteins / metabolism*
  • Histocytochemistry
  • Immunoassay
  • Insect Hormones / genetics
  • Insect Hormones / metabolism*
  • Microscopy, Electron
  • Microvilli / metabolism
  • Mutation
  • Photoreceptor Cells / growth & development*
  • Photoreceptor Cells / metabolism
  • Photoreceptor Cells / ultrastructure
  • Recombinant Fusion Proteins / immunology
  • Retina / growth & development*
  • Retina / metabolism
  • Retina / ultrastructure


  • Antibodies, Monoclonal
  • Eye Proteins
  • Insect Hormones
  • Recombinant Fusion Proteins