Complementary gradients in expression and binding of ELF-1 and Mek4 in development of the topographic retinotectal projection map

Cell. 1995 Aug 11;82(3):371-81. doi: 10.1016/0092-8674(95)90426-3.


Topographic maps with a defined spatial ordering of neuronal connections are a key feature of brain organization. Such maps are believed to develop in response to complementary position-specific labels in presynaptic and postsynaptic fields. However, the complementary labeling molecules are not known. In the well-studied visual map of retinal axons projecting to the tectum, the labels are hypothesized to be in gradients, without needing large numbers of cell-specific molecules. We recently cloned ELF-1 as a ligand for Eph family receptors. Here, RNA hybridization shows matching expression gradients for ELF-1 in the tectum and its receptor Mek4 in the retina. Binding activity detected with alkaline phosphatase fusions of ELF-1 and Mek4 also reveals gradients and provides direct evidence for molecular complementarity of gradients in reciprocal fields. ELF-1 and Mek4 may therefore play roles in retinotectal development and have properties predicted of topographic mapping labels.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Brain Mapping*
  • Chickens
  • Ephrin-A2
  • Mice
  • Molecular Sequence Data
  • Proteins / isolation & purification
  • Proteins / physiology*
  • Retinal Ganglion Cells / physiology*
  • Sequence Homology, Amino Acid
  • Superior Colliculi / embryology
  • Superior Colliculi / physiology*


  • Ephrin-A2
  • Proteins

Associated data

  • GENBANK/L40932