Lineage-Specific Requirements Of Alx4 Function In Craniofacial And Hair Development

The study investigates the role of ALX4 in craniofacial and hair development using conditional mice models. It reveals that tissue-specific inactivation of Alx4 in cranial neural crest and limb bud mesenchyme leads to developmental defects similar to those in Alx4-null mice, but without affecting survival. Notably, Alx4-null mice that survive postnatally show dorsal alopecia, while mice with neural crest-specific Alx4 inactivation have localized hair loss on the anterior skull. In contrast, mice with Alx4 inactivation in the cranial mesoderm show normal hair development. This suggests that Alx4 has partly redundant roles in different cell lineages during hair follicle development. The findings provide a framework for further exploration of ALX transcription factors in development and disease.