Craniofacial neural crest cell-specific deletion of Ihh causes skeletal malocclusion in mice

Although our data is providing the evidence that Ihh regulates nasal and mandibular cartilage development to establish facial and masticatory system, the cartilage gene network conducted by Ihh signaling has not been broadly investigated. To establish such gene expression profile, we selected mandibular condylar cartilage to examine differentiating cartilage tissue. The cartilage histologically indicates simple endochondral ossification and mutant sections positive to Tomato staining presented decreased and disrupted cartilage. Condylar cartilages dissected under microscope from both control and mutant groups were processed and the total RNA was subjected to RNA Seq analysis. In parallel, mutant condylar samples were confirmed by Ihh, Cre and Tomato expression analysis.尽管已有数据证实印度猬蛋白（Indian Hedgehog, Ihh）可调控鼻腔与下颌软骨的发育，进而构建面部结构与咀嚼系统，但Ihh信号通路介导的软骨基因调控网络尚未得到广泛研究。为构建该基因表达谱，我们选取下颌髁突软骨作为研究对象，以分析处于分化阶段的软骨组织。该类软骨在组织学上呈现典型的单纯软骨内骨化特征；而经Tomato染色呈阳性的突变组切片，其软骨组织出现了数量减少与结构破坏的表型。我们通过显微解剖获取对照组与突变组的髁突软骨，随后提取总RNA并进行RNA测序（RNA Seq）分析。与此同时，我们通过检测Ihh、Cre及Tomato的表达水平，对突变组髁突样本进行了验证。