RNA dynamics in the developing mouse face

描述（申请人提供）：颅面形态发生是一个复杂的过程，需要六个不同的面部突出部位协调增殖、运动和分化。这一过程的复杂性使其容易受到环境和遗传的干扰，因此颅面畸形是最常见的出生缺陷之一。面部突出由单层外胚层包裹着神经嵴和中胚层来源的间充质细胞组成。这一小群外胚层细胞发出的信号指导和协调底层间质的行为，从而促进面部形态的形成。改变这些信号过程和组织相互作用的操作对面部发育有严重后果，导致各种类型的医学上重要的畸形，包括口面部裂。因此，外胚层基因动力学的详细知识是面部发育总体描述的重要组成部分。在这个应用程序中，一个多学科的团队聚集了颅面生物学，小鼠分子遗传学，生物信息学和计算机生物学的专业知识，以获得系统生物学水平的早期哺乳动物面部发育的理解。在Aim 1中，野生型面部突出的外胚层和间质将在包含面部形态发生的关键时间点分离，然后这些分离的组织将被用来生成染色质特征、基因表达和翻译的动态时空剖面。这些研究将扩展到通过干扰面部外胚层内的关键信号通路和调节机制来进行异常发育。在这方面，来自小鼠模型的新证据表明，组织特异性上皮剪接因子的缺失导致了口面部裂。在Aim 2中，这些小鼠将被用来询问依赖这些Esrp蛋白来指导正常面部发育的替代切片转录本（Aim 2）。这些变化如何改变外胚层的转录水平和转录异构体，以及这随后如何影响潜在的间质将被详细研究。这些研究应该为外胚层和间质在正常面部发育和颅面畸形中的动态相互作用提供有价值的资源。外胚层内的组织特异性基因缺失是干扰正常面部发育的另一种方式。基于Hedgehog， Wnt和Fgf信号通路的小鼠模型可在外胚层解除管制后产生严重的颅面缺陷。这些模型将在Aim 3中进行研究，以研究支撑面部发育的关键上皮：间充质相互作用。

DESCRIPTION (provided by applicant): Craniofacial morphogenesis is a complex process requiring coordinated proliferation, movement and differentiation of six distinct facial prominences. The complexity of this process leaves it vulnerable to environmental and genetic perturbations, such that craniofacial malformations are one of the most common classes of birth defects. Facial prominences are made up of a mono-layer of ectoderm encasing a large core of neural crest- and mesodermally-derived mesenchymal cells. Signaling from this minor population of ectodermal cells directs and coordinates the behavior of the underlying mesenchyme, and thence facial morphogenesis. Manipulations that alter these signaling processes and tissue interactions have grave consequences for facial development, resulting in various types of medically important dysmorphology including orofacial clefting. Thus a detailed knowledge of geno-dynamics of the ectoderm is an essential component of the overall description of facial development. In this application a multi-disciplinary team has been assembled with expertise in craniofacial biology, mouse molecular genetics, bioinformatics and computer biology to gain a Systems Biology level understanding of early mammalian facial development. In Aim 1, the ectoderm and the mesenchyme of the wild-type facial prominences will be separated at critical timepoints encompassing facial morphogenesis, then these separated tissues will be used to generate contrasting dynamic spatio-temporal profiles of chromatin signatures, gene expression and translation. These studies will then be extended to abnormal development by perturbing crucial signaling pathways and regulatory mechanisms within the facial ectoderm. In this respect, new evidence from mouse models indicates that loss of tissue-specific epithelial splicing factors results in orofacial clefting. In Aim 2, these mice ill be used to interrogate the alternatively sliced transcripts that rely upon these Esrp proteins to direct normal facial development (Aim 2). How these changes alter transcript levels and transcript isoforms in the ectoderm, and how this subsequently impacts the underlying mesenchyme will be studies in detail. These studies should provide a valuable resource detailing the dynamic interplay of ectoderm and mesenchyme in both normal facial development and craniofacial deformity. Tissue-specific of deletion of genes within the ectoderm is a further way to perturb normal facial development. Mouse models are available based on the Hedgehog, Wnt and Fgf signaling pathways that development serious craniofacial defects upon deregulation in the ectoderm. These models will be studied in Aim 3 to investigate the critical epithelial:mesenchymal interactions underpinning facial development.