OBJECTIVE: This study aimed to explore the heterogeneity and gene ontology of Wnt1-Cre-marked and Pax2-Cre-marked first branchial arch cranial neural crest cells (CNCs) in mice.
METHODS: The embryos of Wnt1-Cre;R26RmTmG and Pax2-Cre;R26RmTmG at embryonic day (E)8.0-E9.25 were collected for histological observation. We performed immunostaining to compare green fluorescent protein (GFP)-positive CNCs in Pax2-Cre;R26RAi9 and Wnt1-Cre;R26RAi9 mice at E15.5. Single-cell RNA sequencing (scRNA-seq) was used to analyze the first branchial arch GFP-positive CNCs from Wnt1-Cre;R26RmTmG and Pax2-cre;R26RmTmGmice at E10.5. Real time fluorescence quantitative polymerase chain reaction (q-PCR) was performed to validate the differential genes.
RESULTS: Wnt1-Cre-marked and Pax2-Cre-marked CNCs migrated from the neural plateto first and second branchial arches and to the first branchial arch, respectively, at E8.0. Although Wnt1-Cre-marked and Pax2-Cre-marked CNCs were found mostly in cranial-facial tissues, the former had higher expression in palate and tongue. The results of scRNA-seq showed that Pax2-Cre-marked CNCs specifically contributed to osteoblast differentiation and ossification, while Wnt1-Cre-marked CNCs participated in limb development, cell migration, and ossification. The q-PCR data also confirmed the results of gene ontology analysis.
CONCLUSIONS: Pax2-Cre mice are perfect experimental animal models for research on first branchial arch CNCs and derivatives in osteoblast differentiation and ossification.
目的: 利用Wnt1-Cre和Pax2-Cre小鼠特异性标记颅颌面神经嵴细胞(CNCs)迁移到第一鳃弓时的分化异质性及机制。方法: 分别收取胚胎期(E)8.0~E9.25 Wnt1-Cre;R26RmTmG及Pax2-Cre;R26RmTmG小鼠胚胎进行整体荧光观察,利用石蜡切片免疫荧光对E15.5的Pax2-Cre;R26RAi9和Wnt1-Cre;R26RAi9小鼠所标记的CNCs在颅面部主要组织器官中的谱系分化情况进行比较分析,最后对E10.5的Wnt1-Cre;R26RmTmG和Pax2-Cre;R26RmTmG小鼠的第一鳃弓组织中CNCs进行单细胞测序分析,并对差异基因进行荧光定量聚合酶链反应(q-PCR)验证。结果: Pax2-Cre和Wnt1-Cre小鼠特异性标记的CNCs均在E8.0自神经板开始迁移,但Pax2-Cre小鼠仅标记迁移到第一鳃弓的CNCs,而Wnt1-Cre同时标记了迁移到第一和第二鳃弓的CNCs;在分化谱系示踪方面,二者皆标记了CNCs分化形成的颅颌面部组织器官的间充质,但Wnt1-Cre在上腭和舌中标记CNCs更多;在第一鳃弓间充质中,Pax2-Cre所标记的CNCs特异性表达基因主要参与了成骨,而Wnt1-Cre所标记的CNCs特异性表达基因主要参与了肢体发育、细胞迁移和成骨,q-PCR结果也证实了两者高表达差异基因参与了以上功能。结论: 本研究结果提示Pax2-Cre小鼠可特异性用于第一鳃弓CNCs及其衍生组织成骨方面的研究。.