PUBLICATION

Role of hlx1 in zebrafish brain morphogenesis

Authors
Hjorth, J.T., Connor, R.M., and Key, B.
ID
ZDB-PUB-020807-8
Date
2002
Source
The International journal of developmental biology   46(4): 583-596 (Journal)
Registered Authors
Key, Brian
Keywords
none
MeSH Terms
  • Animals
  • Axons/metabolism
  • Body Patterning
  • Brain/embryology*
  • Brain/metabolism
  • Cloning, Molecular
  • DNA, Complementary/metabolism
  • Gene Expression Regulation, Developmental*
  • Gene Library
  • Homeodomain Proteins/biosynthesis*
  • Homeodomain Proteins/genetics
  • Homeodomain Proteins/physiology*
  • Immunohistochemistry
  • In Situ Hybridization
  • Microscopy, Confocal
  • Models, Biological
  • Nerve Tissue Proteins/metabolism
  • Neurons/cytology
  • Oligonucleotides, Antisense/pharmacology
  • Phenotype
  • Rhombencephalon/embryology
  • Time Factors
  • Transcription Factors/biosynthesis*
  • Transcription Factors/genetics
  • Transcription Factors/metabolism
  • Transcription Factors/physiology*
  • Zebrafish
  • Zebrafish Proteins/metabolism
PubMed
12141447
Abstract
hlx1 is a related homeobox gene expressed in a dynamic spatiotemporal expression pattern during development of the zebrafish brain. The homologues of hlx1, mouse dbx1 and Xenopus Xdbx, are known to play a role in the specification of neurons in the spinal cord. However, the role of these molecules in the brain is less well known. We have used two different approaches to elucidate a putative function for hlx1 in the developing zebrafish brain. Blastomeres were injected with either synthetic hlx1 mRNA in gain-of-function experiments or with antisense morpholino oligonucleotides directed against hlx1 in loss-of-function experiments. Mis-expression of hlx1 produced severe defects in brain morphogenesis as a result of abnormal ventricle formation, a phenotype we referred to as "fused-brain". These animals also showed a reduction in the size of forebrain neuronal clusters as well as abnormal axon pathfinding. hlx1 antisense morpholinos specifically perturbed hindbrain morphogenesis leading to defects in the integrity of the neuroepithelium. While hindbrain patterning was in the most part unaffected there were select disruptions to the expression pattern of the neurogenic gene Zash1B in specific rhombomeres. Our results indicate multiple roles for hlx1 during zebrafish brain morphogenesis.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping