Understanding the development of oral epithelial organs through single cell transcriptomic analysis. Understanding the development of oral epithelial organs through single cell transcriptomic analysis

During vertebrate craniofacial development, the oral epithelium begins as a simple and morphologically homogeneous tissue. It then gives rise to locally complex structures, including the developing teeth, salivary glands, and taste buds. While there is significant knowledge about the molecular mechanisms regulating the morphogenesis of these organs at later stages, how the epithelium is initially patterned and specified to generate diverse cell types and organs remains largely unknown. To elucidate the genetic programs that direct the formation of distinct oral epithelial populations, we conducted single cell RNA-sequencing using mandibular epithelia from embryonic day (E) 12.0 mouse embryos and whole mandibles from E9.5 mouse embryos. The goal of this study is therefore to generate a detailed transcriptional atlas of the developing mandibular epithelium. Overall design: For the E12.0 epithelial dataset, mandibular epithelial cells from six K14Cre;R26mT/mG mouse embryos from the same litter were separated from the mesenchyme, dissociated and sorted using fluorescence-activated cell sorting (FACS) to isolate GFP+ single epithelial cells. The single pooled population was analyzed using 10X scRNA-seq. For the E9.5 dataset, mandibular arches including both the epithelium and mesenchyme were dissected from eight embryos and dissociated. The single pooled population was analyzed using 10X scRNA-seq.

在脊椎动物颅面发育过程中，口腔上皮（oral epithelium）最初是一种结构简单且形态均一的组织，随后可分化形成局部结构复杂的组织，包括发育中的牙齿、唾液腺与味蕾。尽管目前对于后期这些器官形态发生的分子调控机制已有较为充分的认知，但口腔上皮最初是如何被模式化并特化以产生多样细胞类型与器官的，这一问题仍在很大程度上未被阐明。为阐明调控不同口腔上皮群体形成的遗传程序，本研究使用来自胚胎期12.0天（E12.0）小鼠胚胎的下颌上皮，以及来自E9.5小鼠胚胎的完整下颌骨开展单细胞RNA测序（single cell RNA-sequencing）。因此本研究的目标是构建发育中下颌上皮的高精度转录组图谱。
实验设计概况：
针对E12.0上皮数据集：从同窝的6只K14Cre;R26mT/mG小鼠胚胎中分离下颌上皮细胞，将其与间充质（mesenchyme）分离后解离，再通过荧光激活细胞分选（fluorescence-activated cell sorting, FACS）分离出GFP阳性的单个上皮细胞，随后采用10X scRNA-seq对混合后的单细胞群体进行分析。
针对E9.5数据集：从8枚胚胎中剥离包含上皮与间充质的下颌弓（mandibular arches）并进行解离，同样采用10X scRNA-seq对混合后的单细胞群体进行分析。