Induction in the developing compound eye of Drosophila: multiple mechanisms restrict R7 induction to a single retinal precursor cell

Cell. 1991 Dec 20;67(6):1145-55. doi: 10.1016/0092-8674(91)90291-6.


The development of the Drosophila R7 photoreceptor cell is determined by a specific inductive interaction between the R8 photoreceptor cell and a single neighboring precursor cell. This process is mediated by bride of sevenless (boss), a cell-surface bound ligand, and the sevenless (sev) tyrosine kinase receptor. The boss ligand is expressed specifically on the surface of the R8 cell, whereas the sev receptor is expressed on 5 cells contacting the developing R8 cell and other cells not in contact with R8. By altering the spatial and temporal expression of boss, we demonstrate that sev-expressing cells that do not contact R8 can assume an R7 cell fate. By contrast, the sev-expressing precursor cells to the R1-R6 photoreceptor cells that do contact R8 are nonresponsive to the inductive cue. Using the rough and Nspl mutations, we demonstrate that an early commitment to an R1-R6 cell fate blocks the pathway of sev activation in these cells.

Publication types

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

MeSH terms

  • Animals
  • Cloning, Molecular
  • Drosophila Proteins*
  • Drosophila melanogaster / embryology*
  • Embryonic Induction
  • Eye / embryology
  • Eye Proteins / physiology*
  • Gene Expression
  • Ligands
  • Membrane Glycoproteins / physiology*
  • Membrane Proteins / physiology*
  • Neurons / cytology
  • Photoreceptor Cells / cytology
  • Photoreceptor Cells / embryology*
  • Protein-Tyrosine Kinases / physiology
  • Receptor Protein-Tyrosine Kinases*
  • Receptors, Peptide*


  • Drosophila Proteins
  • Eye Proteins
  • Ligands
  • Membrane Glycoproteins
  • Membrane Proteins
  • Receptors, Peptide
  • boss protein, Drosophila
  • Protein-Tyrosine Kinases
  • Receptor Protein-Tyrosine Kinases
  • sev protein, Drosophila