Data from: Signals from the brain and olfactory epithelium control shaping of the mammalian nasal capsule cartilage

Facial shape is the basis for facial recognition and categorization.
Facial features reflect the underlying geometry of the skeletal
structures. Here we reveal that cartilaginous nasal capsule (corresponding
to upper jaw and face) is shaped by signals generated by neural
structures: brain and olfactory epithelium. Brain-derived Sonic Hedgehog
(SHH) enables the induction of nasal septum and posterior nasal capsule,
whereas the formation of a capsule roof is controlled by signals from the
olfactory epithelium. Unexpectedly, the cartilage of the nasal capsule
turned out to be important for shaping membranous facial bones during
development. This suggests that conserved neurosensory structures could
benefit from protection and have evolved signals inducing cranial
cartilages encasing them. Experiments with mutant mice revealed that the
genomic regulatory regions controlling production of SHH in the nervous
system contribute to facial cartilage morphogenesis, which might be a
mechanism responsible for the adaptive evolution of animal faces and
snouts.