PRDM3 and PRDM16 define cranial neural crest cell states in zebrafish development.

Area of Science:

• Developmental Biology
• Epigenetics
• Molecular Biology

Background:

• Craniofacial and peripheral nervous system development relies on cranial neural crest cells.
• Cell differentiation involves complex genetic and epigenetic regulatory networks.
• Histone modifiers like Prdm3 and Prdm16 play crucial roles in these processes.

Purpose of the Study:

• To investigate the direct transcriptional targets of Prdm3 and Prdm16 in zebrafish neural crest cells.
• To determine the mechanism of action for Prdm3 and Prdm16 in regulating gene expression.

Main Methods:

• Chromatin Unbound and Released by Nuclease (CUT&RUN) assay to assess DNA binding and nucleosome association.
• CUT&RUN fragment size analysis to determine protein-nucleosome interaction.
• In situ hybridization chain reaction (HCR) to validate gene expression changes.
• CUT&RUN-qPCR to confirm binding at target loci in mutant embryos.

Main Results:

• Prdm3 and Prdm16 are primarily associated with nucleosomes in zebrafish neural crest cells at 48 hours post fertilization.
• Six distinct clusters of nucleosome peaks revealed differential binding of Prdm3/Prdm16 and associated gene ontology terms.
• prdm3 and prdm16 mutants displayed corresponding alterations in the expression of identified target genes.
• CUT&RUN-qPCR confirmed reduced binding of Prdm3 and Prdm16 at their putative target loci in mutant embryos.

Conclusions:

• Prdm3 and Prdm16 regulate transcriptional targets mainly through nucleosome binding.
• This nucleosome association is critical for controlling downstream gene expression in neural crest development.
• The findings elucidate the epigenetic mechanisms governing neural crest cell differentiation.