The alx gene family confers segmental identity to frontonasal cranial neural crest cells (opens in new tab)

Cranial neural crest cells in the pharyngeal arches give rise to vertebrate head skeletal structures. Hox genes confer segmental identity to the different arches, and Hox mutations result in mirror-image homeotic duplications. Frontonasal cranial neural crest cells reside anterior to the first pharyngeal arch, give rise to the midface skeleton, and are not considered part of the segmental series. Here, we demonstrate that alx genes confer segmental identity to this anterior-most population in...