ZFIN ID: ZDB-PUB-070523-18
Genetic single-cell mosaic analysis implicates ephrinB2 reverse signaling in projections from the posterior tectum to the hindbrain in zebrafish
Sato, T., Hamaoka, T., Aizawa, H., Hosoya, T., and Okamoto, H.
Date: 2007
Source: The Journal of neuroscience : the official journal of the Society for Neuroscience 27(20): 5271-5279 (Journal)
Registered Authors: Aizawa, Hidenori, Okamoto, Hitoshi, Sato, Tomomi
Keywords: zebrafish, tectobulbar projection, Cre/loxP, Gal4/UAS, ephrinB, reverse signaling
MeSH Terms:
  • Animals
  • Animals, Genetically Modified
  • Ephrin-B2/genetics
  • Ephrin-B2/physiology*
  • Mosaicism*/embryology
  • Neurons/cytology
  • Neurons/physiology*
  • Rhombencephalon/cytology
  • Rhombencephalon/embryology
  • Rhombencephalon/physiology*
  • Signal Transduction/genetics
  • Superior Colliculi/cytology
  • Superior Colliculi/embryology
  • Superior Colliculi/physiology*
  • Visual Pathways/cytology
  • Visual Pathways/embryology
  • Visual Pathways/physiopathology
  • Zebrafish
  • Zebrafish Proteins/biosynthesis
  • Zebrafish Proteins/genetics*
PubMed: 17507550 Full text @ J. Neurosci.
The optic tectum is a visual center in vertebrates. It receives topographically ordered visual inputs from the retina in the superficial layers and then sends motor outputs from the deeper layers to the premotor reticulospinal system in the hindbrain. Although the topographic patterns of the retinotectal projection are well known, it is not yet well understood how tectal efferents in the tectobulbar tract project to the hindbrain. The retinotectal and the tectobulbar projections were visualized in a zebrafish stable transgenic line Tg(brn3a-hsp70:GFP). Using a single-neuron labeling system in combination with the cre/loxP and Gal4/UAS systems, we showed that the tectal neurons that projected to rhombomeres 2 and 6 were distributed with distinctive patterns along the anterior-posterior axis. Furthermore, we found that ephrinB2a was critically involved in increasing the probability of neurons projecting to rhombomere 2 through a reverse signaling mechanism. These results may provide a neuroanatomical and molecular basis for the motor command map in the tectum.