The receptor tyrosine kinase Off-track is required for layer-specific neuronal connectivity in Drosophila

Development. 2004 Nov;131(21):5287-95. doi: 10.1242/dev.01406. Epub 2004 Sep 29.

Abstract

The nervous system in many species consists of multiple neuronal cell layers, each forming specific connections with neurons in other layers or other regions of the brain. How layer-specific connectivity is established during development remains largely unknown. In the Drosophila adult visual system, photoreceptor (R cell) axons innervate one of two optic ganglia layers; R1-R6 axons connect to the lamina layer, while R7 and R8 axons project through the lamina into the deeper medulla layer. Here, we show that the receptor tyrosine kinase Off-track (Otk) is specifically required for lamina-specific targeting of R1-R6 axons. Otk is highly expressed on R1-R6 growth cones. In the absence of otk, many R1-R6 axons connect abnormally to medulla instead of innervating lamina. We propose that Otk is a receptor or a component of a receptor complex that recognizes a target-derived signal for R1-R6 axons to innervate the lamina layer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aging / physiology
  • Animals
  • Axons / metabolism
  • Body Patterning
  • Cell Differentiation
  • Cell Lineage
  • Cell Movement
  • Drosophila Proteins / metabolism*
  • Drosophila melanogaster / cytology*
  • Drosophila melanogaster / enzymology*
  • Drosophila melanogaster / growth & development
  • Eye / cytology
  • Eye / enzymology
  • Eye / growth & development
  • Growth Cones / enzymology
  • Mutation / genetics
  • Neuroglia / cytology
  • Neuroglia / metabolism
  • Neurons / cytology*
  • Neurons / physiology*
  • Receptor Protein-Tyrosine Kinases / metabolism*
  • Semaphorins / metabolism
  • Signal Transduction

Substances

  • Drosophila Proteins
  • Semaphorins
  • Otk protein, Drosophila
  • Receptor Protein-Tyrosine Kinases