ZFIN ID: ZDB-PUB-020114-1
The zebrafish trilobite gene is essential for tangential migration of branchiomotor neurons
Bingham, S., Higashijima, S.-I., Okamoto, H., and Chandrasekhar, A.
Date: 2002
Source: Developmental Biology   242(2): 149-160 (Journal)
Registered Authors: Bingham, Stephanie, Chandrasekhar, Anand, Higashijima, Shin-ichi, Okamoto, Hitoshi
Keywords: zebrafish; hindbrain; motor neuron; tangential; radial; neuronal migration; gastrulation; rhombomere; green fluorescent protein; time-lapse microscopy
MeSH Terms:
  • Animals
  • Branchial Region/cytology*
  • Cell Movement/genetics*
  • Green Fluorescent Proteins
  • Immunohistochemistry
  • Luminescent Proteins/genetics
  • Motor Neurons/cytology*
  • Mutation
  • Rhombencephalon/cytology
  • Zebrafish/genetics*
PubMed: 11820812 Full text @ Dev. Biol.
Newborn neurons migrate extensively in the radial and tangential directions to organize the developing vertebrate nervous system. We show here that mutations in zebrafish trilobite (tri) that affect gastrulation-associated cell movements also eliminate tangential migration of motor neurons in the hindbrain. In the wild-type hindbrain, facial (nVII) and glossopharyngeal (nIX) motor neurons are induced in rhombomeres 4 and 6, respectively, and migrate tangentially into r6 and r7 (nVII) and r7 (nIX). In all three tri alleles examined, although normal numbers of motor neurons are induced, nVII motor neurons are found exclusively in r4, and nIX-like motor neurons are found exclusively in r6. The migration of other neuronal and nonneuronal cell types is unaffected in tri mutants. Rhombomere formation and the development of other hindbrain neurons are also unaffected in tri mutants. Furthermore, tangential neuronal migration occurs normally in the gastrulation mutant knypek, indicating that the trilobite neuron phenotype does not arise nonspecifically from aberrant gastrulation-associated movements. We conclude that trilobite function is specifically required for two types of cell migration that occur at different stages of zebrafish development.