Effects of Dlx2 Overexpression on the Genome of Maxillary Process in Early Embryo of Mice [OE Bulk RNA-seq]. Effects of Dlx2 Overexpression on the Genome of Maxillary Process in Early Embryo of Mice [OE Bulk RNA-seq]

Transcription factor Dlx2 plays an important role in craniomaxillofacial development. Overexpression or null mutation can lead to craniomaxillofacial malformation in mice. Although some in vivo or in vitro experiments have explored part information about the mechanism of Dlx2 regulation, there is still a lack of complete description. Using a mouse model that can stably overexpress Dlx2 in neural crest cells, the authors conducted bulk RNA-Seq, scRNA-Seq and CUT&Tag on the early maxillary processes of mice, and comprehensively described the effects of Dlx2 overexpression on the early development of maxillary processes. Bulk RNA-Seq results showed that Dlx2 had greater interference on nerve development at E10.5, and gradually affected bone development at E12.5. ScRNA-Seq proved that overexpression of Dlx2 did not change the differentiation type of mesenchymal cells during this development process, but it would restrict the proliferation of cells and make mesenchymal cells differentiate prematurely, thus limiting the development of maxillary. CUT&Tag suggested that this regulatory process is closely related to Notch signaling pathway, and MNT and RUNX2, as direct downstream regulatory target genes of Dlx2, also play a very critical role. Overall design: Using a Dlx2 overexpression mouse model, the authors conducted bulk RNA Seq on the maxillary process of E10.5 mice, analyzed the impact of Dlx2 overexpression on genome expression, and compared it with the existing data of E12.5 mouse maxillary process in GEO database.

转录因子Dlx2在颅颌面发育中具有关键调控作用。在小鼠体内，该基因的过表达或功能缺失突变均可引发颅颌面畸形。尽管已有部分体内、体外实验对Dlx2的调控机制开展了探索，但目前仍缺乏完整的机制阐释。研究团队构建了可在神经嵴细胞中稳定过表达Dlx2的小鼠模型，对小鼠早期上颌突开展批量RNA测序（bulk RNA-Seq）、单细胞RNA测序（scRNA-Seq）及CUT&Tag测序，并全面阐释了Dlx2过表达对上颌突早期发育的影响。批量RNA测序结果显示，Dlx2过表达在胚胎第10.5天（E10.5）对神经发育产生较强干扰，并在胚胎第12.5天（E12.5）逐渐影响骨组织发育。单细胞RNA测序结果表明，在该发育过程中，Dlx2过表达并未改变间充质细胞的分化类型，但会抑制细胞增殖并促使间充质细胞提前分化，进而限制上颌突发育。CUT&Tag测序结果显示，该调控过程与Notch信号通路密切相关，而作为Dlx2直接下游调控靶基因的MNT与RUNX2，同样发挥了至关重要的作用。
整体实验设计：研究团队借助Dlx2过表达小鼠模型，对胚胎第10.5天小鼠的上颌突开展批量RNA测序，分析Dlx2过表达对基因组表达的影响，并与基因表达综合数据库（Gene Expression Omnibus, GEO）中已公开的胚胎第12.5天小鼠上颌突测序数据进行比对。