New transgenic reporters identify somatosensory neuron subtypes in larval zebrafish

Dev Neurobiol. 2013 Feb;73(2):152-67. doi: 10.1002/dneu.22049. Epub 2012 Sep 27.

Abstract

To analyze somatosensory neuron diversity in larval zebrafish, we identified several enhancers from the zebrafish and pufferfish genomes and used them to create five new reporter transgenes. Sequential deletions of three of these enhancers identified small sequence elements sufficient to drive expression in zebrafish trigeminal and Rohon-Beard (RB) neurons. One of these reporters, using the Fru.p2x3-2 enhancer, highlighted a somatosensory neuron subtype that expressed both the p2rx3a and pkcα genes. Comparison with a previously described trpA1b reporter revealed that it highlighted the same neurons as the Fru.p2x3-2 reporter. To determine whether neurons of this subtype possess characteristic peripheral branching morphologies or central axon projection patterns, we analyzed the morphology of single neurons. Surprisingly, although these analyses revealed diversity in peripheral axon branching and central axon projection, PKCα/p2rx3a/trpA1b-expressing RB cells did not possess obvious characteristic morphological features, suggesting that even within this molecularly defined subtype, individual neurons may possess distinct properties. The new transgenes created in this study will be powerful tools for further characterizing the molecular, morphological, and developmental diversity of larval somatosensory neurons.

Publication types

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

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Axons / physiology
  • Cloning, Molecular
  • Embryo, Nonmammalian
  • Genes, Reporter / genetics*
  • Green Fluorescent Proteins / genetics
  • In Situ Hybridization, Fluorescence
  • Larva / physiology*
  • Microscopy, Confocal
  • Peripheral Nervous System / cytology
  • Peripheral Nervous System / embryology
  • Protein Kinase C-alpha / biosynthesis
  • Protein Kinase C-alpha / genetics
  • Receptor, trkA / genetics
  • Sensory Receptor Cells / classification
  • Sensory Receptor Cells / physiology*
  • Species Specificity
  • Takifugu
  • Transgenes / genetics*
  • Trigeminal Nerve / embryology
  • Trigeminal Nerve / growth & development
  • Zebrafish / genetics*
  • Zebrafish / metabolism

Substances

  • Green Fluorescent Proteins
  • Receptor, trkA
  • Protein Kinase C-alpha