Generation of tamoxifen‐inducible Tfap2b‐CreER^T2 mice using CRISPR‐Cas9

Abstract

SummaryTfap2b, 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‐CreERT2 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‐CreERT2 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.

Single-cell profiling of penta- and tetradactyl mouse limb buds identifies mesenchymal progenitors controlling digit numbers and identities

“…13,71 In contrast to Hoxa13 and Jag1 , Tfap2b expression is much more restricted and a recent study shows that the Tfap2b lineage contributes to digits. 72,73 Therefore, our single cell analysis identifies triple-positive Hoxa13 + Jag1 + Tfap2b + dLMPs as early GREM1-dependent digit progenitors in mouse and pig limb buds. Moreover, dLMP signature genes are also detected in autopodial cell signatures of human limb buds.…”