Tfap2b, a pivotal transcription factor, plays critical roles within neural crest cells and their derived lineage. To unravel the intricate lineage dynamics and contribution of these Tfap2b+ cells during craniofacial development, we established a Tfap2b-CreER^T2 knock-in transgenic mouse line using the CRISPR-Cas9-mediated homologous direct repair. By breeding with tdTomato reporter mice and initiating Cre activity through tamoxifen induction at distinct developmental time points, we show the Tfap2b lineage within the key neural crest-derived domains, such as the facial mesenchyme, midbrain, cerebellum, spinal cord, and limbs. Notably, the migratory neurons stemming from the dorsal root ganglia are visible subsequent to Cre activity initiated at E8.5. Intriguingly, Tfap2b+ cells, serving as the progenitors for limb development, show activity predominantly commencing at E10.5. Across the mouse craniofacial landscape, Tfap2b exhibits a widespread presence throughout the facial organs. Here we validate its role as a marker of progenitors in tooth development and have confirmed that this process initiates from E12.5. Our study not only validates the Tfap2b-CreER^T2 transgenic line, but also provides a powerful tool for lineage tracing and genetic targeting of Tfap2b-expressing cells and their progenitor in a temporally and spatially regulated manner during the intricate process of development and organogenesis.

中文翻译：

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使用 CRISPR-Cas9 生成他莫昔芬诱导的 Tfap2b-CreERT2 小鼠

Tfap2b 是一种关键转录因子，在神经嵴细胞及其衍生谱系中发挥着关键作用。为了揭示这些 Tfap2b+ 细胞在颅面发育过程中复杂的谱系动态和贡献，我们使用 CRISPR-Cas9 介导的同源直接修复建立了Tfap2b-CreER ^T2敲入转基因小鼠系。通过与 tdTomato 报告小鼠繁殖，并在不同的发育时间点通过他莫昔芬诱导启动 Cre 活性，我们在关键的神经嵴衍生区域（例如面部间质、中脑、小脑、脊髓和四肢）内显示了Tfap2b谱系。值得注意的是，在 E8.5 启动 Cre 活动后，可以看到源自背根神经节的迁移神经元。有趣的是，Tfap2b+ 细胞作为肢体发育的祖细胞，显示出主要从 E10.5 开始的活性。在小鼠颅面部景观中，Tfap2b 在整个面部器官中广泛存在。在这里，我们验证了它作为牙齿发育中祖细胞标记的作用，并确认该过程从 E12.5 开始。我们的研究不仅验证了Tfap2b-CreER ^T2转基因系，而且还为在复杂的发育和器官发生过程中以时间和空间调节的方式对Tfap2b表达细胞及其祖细胞进行谱系追踪和遗传靶向提供了强大的工具。