Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
Department of Molecular Neurosciences, Medical University Vienna, Vienna, Austria.
Elife. 2018 Jun 13;7:e34465. doi: 10.7554/eLife.34465.
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.
面部形状是面部识别和分类的基础。面部特征反映了骨骼结构的潜在几何形状。在这里，我们揭示了软骨性鼻囊（对应于上颌和面部）的形状是由神经结构产生的信号决定的：大脑和嗅上皮。大脑衍生的 Sonic Hedgehog（SHH）能够诱导鼻中隔和后鼻囊的形成，而胶囊顶的形成则受嗅上皮信号的控制。出乎意料的是，鼻囊的软骨在发育过程中对面膜骨的形成很重要。这表明保守的神经感觉结构可能受益于保护，并进化出诱导包裹它们的颅软骨的信号。对突变小鼠的实验表明，控制神经系统中 SHH 产生的基因组调控区域有助于面部软骨形态发生，这可能是动物面部和鼻子适应进化的一种机制。
