Nr2f-dependent allocation of ventricular cardiomyocyte and pharyngeal muscle progenitors

Area of Science:

• Developmental biology
• Molecular genetics
• Cardiovascular research

Background:

• Congenital syndromes often present with shared cardiac and craniofacial muscle defects.
• The precise mechanisms governing the antagonistic lineage decisions between cardiac and pharyngeal muscle progenitors remain unclear.
• Understanding these mechanisms is crucial for deciphering developmental syndromes and congenital heart defects.

Purpose of the Study:

• To elucidate the molecular mechanisms controlling lineage allocation between cardiac and pharyngeal muscle progenitors.
• To investigate the role of retinoic acid signaling and Nr2f transcription factors in this process.
• To provide insights into the etiology of developmental syndromes affecting the heart and face.

Main Methods:

• Utilized zebrafish (Danio rerio) as a model organism.
• Generated and analyzed nr2f1a and nr2f2 mutant zebrafish lines.
• Employed Cre-mediated genetic lineage tracing to track progenitor cell fate.
• Investigated the role of retinoic acid (RA) signaling pathways.

Main Results:

• Identified retinoic acid (RA) signaling as a direct promoter of Nr2f1a expression in the anterior lateral plate mesoderm.
• Demonstrated redundant roles for Nr2f1a and Nr2f2 in restricting ventricular cardiomyocyte (CM) number and promoting posterior pharyngeal muscle (PM) development.
• Showed that in nr2f1a; nr2f2 double mutants, tcf21+ progenitors preferentially differentiate into ventricular CMs over posterior PMs.

Conclusions:

• Nr2f1a and Nr2f2 are key regulators of antagonistic lineage choices between cardiac and pharyngeal muscle progenitors.
• RA signaling, through Nr2f1a, plays a critical role in directing progenitor cell fate.
• These findings offer molecular insights into developmental syndromes with heart and craniofacial defects and the variability of congenital heart defects linked to NR2F mutations.