ZFIN ID: ZDB-PUB-200626-10
Gdnf affects early diencephalic dopaminergic neuron development through regulation of differentiation-associated transcription factors in zebrafish
Wong, C.E.D., Hua, K., Monis, S., Saxena, V., Norazit, A., Noor, S.M., Ekker, M.
Date: 2020
Source: Journal of neurochemistry   156(4): 481-498 (Journal)
Registered Authors: Ekker, Marc, Saxena, Vishal
Keywords: gdnf, crispants, differentiation, dopaminergic neurons, knock-out, neurogenesis, transcription factors, ventral diencephalon
MeSH Terms:
  • Animals
  • Animals, Genetically Modified
  • Cell Differentiation/physiology*
  • Diencephalon/embryology*
  • Diencephalon/metabolism*
  • Dopaminergic Neurons/metabolism*
  • Glial Cell Line-Derived Neurotrophic Factor/deficiency*
  • Glial Cell Line-Derived Neurotrophic Factor/genetics
  • Transcription Factors/deficiency*
  • Transcription Factors/genetics
  • Zebrafish
  • Zebrafish Proteins/deficiency*
  • Zebrafish Proteins/genetics
PubMed: 32583440 Full text @ J. Neurochem.
ABSTRACT
Glial cell line-derived neurotrophic factor (GDNF) has been reported to enhance dopaminergic neuron survival and differentiation in vitro and in vivo, although those results are still being debated. gdnf is highly conserved in zebrafish and plays a role in enteric nervous system function. However, little is known about gdnf function in the teleost brain. Here, we employed CRISPR/Cas9 to impede gdnf function in the maintenance of dopaminergic neuron development. Genotyping of gdnf crispants revealed successful deletions of the coding region with various mutant band sizes and down-regulation of gdnf transcripts at 1, 3 and 7 day(s) post fertilization. Notably, ~20% reduction in ventral diencephalic (vDC) dopaminergic neuron numbers in clusters 8 and 13 was observed in the gdnf-deficient crispants. In addition, gdnf depletion caused a modest reduction in dopaminergic neurogenesis as determined by EdU pulse chase assay. These deleterious effects could be partly attributed to deregulation of dopaminergic neuron fate specification-related transcription factors (otp, lmx1b, shha, and ngn1) in both crispants and established homozygous mutants with whole mount in-situ hybridization (WISH) on gdnf mutants showing reduced otpb and lmx1b.1 expression in the vDC. Interestingly, locomotor function of crispants was only impacted at 7 dpf, but not earlier. Lastly, as expected, gdnf deficiency heightened crispants vulnerability to MPP+ toxic insult. Our results suggest conservation of teleost gdnf brain function with mammals and revealed the interactions between gdnf and transcription factors in dopaminergic neuron differentiation.
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