Tenascin-C is involved in motor axon outgrowth in the trunk of developing zebrafish

Schweitzer, J., Becker, T., Lefebvre, J., Granato, M., Schachner, M., and Becker, C.G.
Developmental Dynamics : an official publication of the American Association of Anatomists   234(3): 550-566 (Journal)
Registered Authors
Becker, Catherina G., Becker, Thomas, Granato, Michael, Lefebvre, Julie, Schachner, Melitta, Schweitzer, Jörn
extracellular matrix, chondroitin sulfate proteoglycans, horizontal myoseptum, primary motor neurons, adaxial cells, stumpy, topped, Danio rerio
MeSH Terms
  • Amino Acid Sequence
  • Animals
  • Axons/chemistry
  • Axons/metabolism*
  • Cell Differentiation
  • Cloning, Molecular
  • Cysteine/metabolism
  • DNA, Complementary/genetics
  • Epidermal Growth Factor/genetics
  • Epidermal Growth Factor/metabolism
  • Gene Expression Regulation, Developmental
  • Humans
  • Immunohistochemistry
  • Molecular Sequence Data
  • Motor Neurons/chemistry
  • Motor Neurons/cytology
  • Motor Neurons/metabolism*
  • Mutation/genetics
  • RNA, Messenger/genetics
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Tenascin/chemistry
  • Tenascin/genetics
  • Tenascin/metabolism*
  • Zebrafish/embryology*
  • Zebrafish/genetics
  • Zebrafish/metabolism*
16110513 Full text @ Dev. Dyn.
Motor axons in the trunk of the developing zebrafish exit from the ventral spinal cord in one ventral root per hemisegment and grow on a common path toward the region of the horizontal myoseptum, where they select their specific pathways. Tenascin-C, a component of the extracellular matrix, is concentrated in this choice region. Adaxial cells and other myotomal cells express tenascin-C mRNA, suggesting that these cells are the source of tenascin-C protein. Overexpressing an axon repellent fragment containing the cysteine-rich region and the epidermal growth factor-like repeats of tenascin-C led to retarded growth of ventral motor nerves between their spinal exit point and the horizontal myoseptum. Injection of a protein fragment containing the same part of tenascin-C also induced slower growth of motor nerves. Conversely, knock down of tenascin-C protein resulted in abnormal lateral branching of ventral motor nerves. In the zebrafish unplugged mutant, in which axons display pathfinding defects in the region of the horizontal myoseptum, tenascin-C immunoreactivity was not detectable in this region, indicating an abnormal extracellular matrix in unplugged. We conclude that tenascin-C is part of a specialized extracellular matrix in the region of the horizontal myoseptum that influences the growth of motor axons.
Genes / Markers
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Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Engineered Foreign Genes