Zebrafish Zic2a and Zic2b regulate neural crest and craniofacial development

Area of Science:

• Developmental Biology
• Genetics
• Craniofacial Development

Background:

• Holoprosencephaly (HPE) is a common forebrain malformation linked to craniofacial defects.
• The zinc-finger transcription factor ZIC2 is associated with HPE and specific facial dysmorphias.
• Previous studies established Zic2's role in zebrafish forebrain development.

Purpose of the Study:

• To investigate the role of zebrafish ZIC2 orthologs (zic2a and zic2b) in craniofacial skeleton development.
• To explore Zic2-regulated processes potentially contributing to HPE etiology.
• To understand Zic2's dual function in neural crest cell development and forebrain patterning.

Main Methods:

• Zebrafish model system utilized for craniofacial and forebrain development studies.
• Temporally controlled Zic2a overexpression experiments.
• Analysis of Zic2 depletion and ectopic expression effects on neural crest cells and craniofacial structures.

Main Results:

• Zebrafish zic2a and zic2b regulate jaw and neurocranial cartilage formation.
• Zic2 influences neural crest induction, migration, and chromatophore development.
• Zebrafish Zic2 plays a dual role in craniofacial morphogenesis, affecting both neural crest development and forebrain patterning.

Conclusions:

• Zebrafish Zic2 orthologs are crucial for craniofacial development, impacting neural crest induction/migration and forebrain patterning.
• Discrepancies in craniofacial patterning observed with altered Zic2 expression are linked to its role in forebrain primordium.
• These findings provide insights into the complex etiology of holoprosencephaly and craniofacial malformations.