PUBLICATION

Beyond the neckless phenotype: influence of reduced retinoic acid signaling on motor neuron development in the zebrafish hindbrain

Authors
Begemann, G., Marx, M., Mebus, K., Meyer, A., and Bastmeyer, M.
ID
ZDB-PUB-040617-4
Date
2004
Source
Developmental Biology   271(1): 119-129 (Journal)
Registered Authors
Bastmeyer, Martin, Begemann, Gerrit, Marx, Monika, Mebus, Katharina, Meyer, Axel
Keywords
Retinaldehyde dehydrogenase, raldh2, Retinoic acid, Hindbrain patterning, Cranial motor neurons, Zebrafish
MeSH Terms
  • Aldehyde Oxidoreductases/genetics
  • Aldehyde Oxidoreductases/physiology*
  • Animals
  • Immunohistochemistry
  • In Situ Hybridization
  • Morphogenesis
  • Motor Neurons/physiology*
  • Phenotype*
  • Retinal Dehydrogenase
  • Rhombencephalon/embryology*
  • Signal Transduction/physiology*
  • Tretinoin/physiology
  • Zebrafish/embryology*
  • p-Aminoazobenzene/analogs & derivatives*
PubMed
15196955 Full text @ Dev. Biol.
Abstract
Retinoic acid (RA) has been identified as a key signal involved in the posteriorization of vertebrate neural ectoderm. The main biosynthetic enzyme responsible for RA signaling in the hindbrain and spinal cord is Raldh2. However, neckless/raldh2-mutant (nls) zebrafish exhibit only mild degrees of anteriorization in the neural ectoderm, compared to full vitamin A deficiency in amniotes and the Raldh2(-/-) mouse. Here we investigated the role of RA during neuronal development in the zebrafish hindbrain and anterior spinal cord using DEAB, an inhibitor of retinaldehyde dehydrogenases. We show that the nls hindbrain and spinal cord are not fully devoid of RA, since blocking Raldh-mediated RA signaling leads to a more severe hindbrain phenotype than in nls. The anteroposterior distribution of branchiomotor neurons in the facial and more posterior nuclei depends on full RA signaling throughout early and late gastrula stages. In contrast, inhibition of RA synthesis after gastrulation reduces the number of branchiomotor neurons in the vagal nucleus, but has no effect on anteroposterior cell fates. In addition, blockage of RA-mediated signaling not only interferes with the differentiation of branchiomotor neurons and their axons in the hindbrain, but also affects the development of the posterior lateral line nerve.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping