Retinoic acid receptors exhibit cell-autonomous functions in cranial neural crest cells

Area of Science:

• Developmental biology
• Genetics
• Molecular biology

Background:

• Retinoic acid (RA) is vital for mesenchymal structure development from neural crest cells (NCC).
• The specific roles of RA receptors (RARs) in NCC development remain incompletely understood.

Purpose of the Study:

• To investigate the cell-autonomous functions of RARs in mouse NCC development.
• To determine the distinct roles of RAR subtypes in cranial NCC patterning.

Main Methods:

• Somatic mutagenesis in mice to selectively ablate RAR genes (RARalpha/RARbeta, RARalpha/RARgamma, RARalpha/RARbeta/RARgamma) in NCC.
• Analysis of NCC survival, migration, and craniofacial and branchial arch development in mutant mice.

Main Results:

• NCC survival and migration are unaffected by RAR ablation until gestational day 10.5.
• Ablation of RARalpha and RARgamma in NCC leads to agenesis of the median face, indicating cell-autonomous control of frontonasal process development.
• Combined ablation of all three RARs in NCC results in less severe branchial arch defects compared to compound null mutants, suggesting RARs act in both NCC and other cell populations.

Conclusions:

• RAR-dependent signaling is not essential for early NCC development but is critical for later patterning.
• RARalpha and RARgamma play cell-autonomous roles in NCC for frontonasal process development.
• RARs utilize distinct mechanisms to pattern cranial NCC, acting both within NCC and in other cell types.