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For decades it has been established that head muscle development differs from trunk muscle development. Similarly known, even though not in such detail, is that different subgroups of head muscles develop dependent on different underlying gene regulatory networks. Even less well studied are the tissue interactions during the developmental processes. Muscles derived from pharyngeal arch mesoderm depend on interactions with endoderm and neural crest cells, and, to a minor extent, ectodermal cues. Extraocular eye muscles respond to a mix of signals from surrounding mesoderm, but also neural crest cells; however, they are independent of endodermal cues. Head muscles derived from occipital paraxial mesoderm depend on tissue interactions similar to pharyngeal arch muscles but have a different migration trajectory. While the pharyngeal arch mesodermal cells and neural crest cells largely migrate from dorsal to ventral, the occipital paraxial mesodermal cells migrate from dorsal to ventral and from posterior to anterior. During the migration these cells proliferate and even start to differentiate, while pharyngeal mesodermal cells begin the differentiation process after reaching their respective pharyngeal arches. Here we present an overview of tissue interactions during the development of different head muscle populations, highlighting general concepts and main differences. Topic Category: Neural Crest, Placodes and Craniofacial Development Keywords: Craniofacial muscles, Myogenesis Funding or Support Information: NSF #2000005 to JMZC
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Generation of tamoxifen‐inducible Tfap2b‐CreERT2 mice using CRISPR‐Cas9
Summary 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 aTfap2b‐CreERT2knock‐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 theTfap2blineage 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 theTfap2b‐CreERT2transgenic line, but also provides a powerful tool for lineage tracing and genetic targeting ofTfap2b‐expressing cells and their progenitor in a temporally and spatially regulated manner during the intricate process of development and organogenesis.
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- Award ID(s):
- 1818107
- PAR ID:
- 10479719
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- genesis
- Volume:
- 62
- Issue:
- 1
- ISSN:
- 1526-954X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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