Zebrafish Embryonic Neurons Transport Messenger RNA to Axons and Growth Cones In Vivo

Marion Baraban, Isabelle Anselme, Sylvie Schneider-Maunoury, Francois Giudicelli

Research output: Contribution to journalArticlepeer-review

Abstract

Although mRNA was once thought to be excluded from the axonal compartment, the existence of protein synthesis in growing or regenerating axons in culture is now generally accepted. However, its extent and functional importance remain a subject of intense investigation. Furthermore, unambiguous evidence of mRNA axonal transport and local translation in vivo, in the context of a whole developing organism is still lacking. Here, we provide direct evidence of the presence of mRNAs of the tubb5, nefma, and stmnb2 genes in several types of axons in the developing zebrafish (Danio rerio) embryo, with frequent accumulation at the growth cone. We further show that axonal localization of mRNA is a specific property of a subset of genes, as mRNAs of the huc and neurod genes, abundantly expressed in neurons, were not found in axons. We set up a reporter system in which the 3' untranslated region (UTR) of candidate mRNA, fused to a fluorescent protein coding sequence, was expressed in isolated neurons of the zebrafish embryo. Using this reporter, we identified in the 3'UTR of tubb5 mRNA a motif necessary and sufficient for axonal localization. Our work thus establishes the zebrafish as a model system to study axonal transport in a whole developing vertebrate organism, provides an experimental frame to assay this transport in vivo and to study its mechanisms, and identifies a new zipcode involved in axonal mRNA localization.

Original languageEnglish
Pages (from-to)15726-15734
Number of pages9
JournalJournal of Neuroscience
Volume33
Issue number40
DOIs
Publication statusPublished - 2 Oct 2013

Keywords

  • LOCAL PROTEIN-SYNTHESIS
  • BINDING PROTEIN
  • FLUORESCENT PROTEIN
  • NERVOUS-SYSTEM
  • GUIDANCE CUES
  • LOCALIZATION
  • TRANSLATION
  • REGENERATION
  • REVEALS
  • ELEMENT

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