Zebrafish PEX1 Is Required for the Generation of GABAergic Neuron in p3 Domain

Area of Science:

• Developmental Neuroscience
• Molecular Biology
• Genetics

Background:

• Notch signaling is crucial for maintaining neural progenitors in vertebrate development.
• Jagged2-mediated Notch signaling supports proliferating neural progenitors in the ventral spinal cord.
• Components of Jagged-mediated signaling during late neurogenesis are not well understood.

Purpose of the Study:

• To identify novel components of Jagged2-mediated Notch signaling.
• To investigate the role of Peroxisome biogenesis factor 1 (PEX1) in neural precursor cell-fate decisions and differentiation.
• To elucidate PEX1's function in the p3 domain during late neurogenesis.

Main Methods:

• Yeast-two hybrid screening using the intracellular domain (ICD) of zebrafish Jagged2.
• Western blotting to confirm physical interaction between zebrafish PEX1 and Jagged2 ICD.
• Morpholino-induced knockdown and CRISPR/Cas9-induced mutation in zebrafish to assess PEX1 function.
• Analysis of neuronal differentiation and cell-fate decisions in the p3 domain.

Main Results:

• Zebrafish PEX1 was identified as a potential interactor of Jagged2 ICD via yeast-two hybrid screening.
• Western blotting indicated a physical interaction between zebrafish PEX1 and Jagged2 ICD.
• PEX1 knockdown or mutation in zebrafish embryos led to an increased number of GABAergic KA" neurons and ectopic expression of secondary motor neurons in the p3 domain.
• Observed phenotypes in PEX1-deficient embryos were similar to those in Jagged2 morphants.

Conclusions:

• PEX1 is implicated as a novel component in the Jagged2-mediated Notch signaling pathway.
• PEX1 plays a critical role in regulating cell-fate decisions of neural precursors in the p3 domain.
• These findings contribute to understanding the molecular mechanisms governing vertebrate nervous system development and neurogenesis.