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，需要协调增殖，移动和分化六个不同的面部隆起。这一过程的复杂性使其容易受到环境和遗传扰动的影响，因此颅面畸形是最常见的出生缺陷之一。面部隆起由一层单层外胚层包裹着一大片神经脊和中胚层来源的间充质细胞组成。来自这一小群外胚层细胞的信号指导和协调底层间充质的行为，并由此产生面部形态发生。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的后果，导致各种类型的医学上重要的畸形，包括口面部裂伤。因此，对外胚层基因动力学的详细了解是全面描述面部发育的重要组成部分。在这项应用中，一个由多学科组成的团队集合了颅面生物学、小鼠分子遗传学、生物信息学和计算机生物学的专业知识，以获得对哺乳动物早期面部发育的系统生物学水平的了解。在目标1中，野生型面部隆起的外胚层和间质将在围绕面部形态发生的关键时间点被分离，然后这些分离的组织将被用来产生染色质特征、基因表达和翻译的对比动态时空轮廓。然后，这些研究将通过干扰面部外胚层内的关键信号通路和调节机制来扩展到异常发育。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丢失会导致口面部分裂。在目标2中，这些小鼠将被用来询问依赖于这些ESRP蛋白来指导正常面部发育的交替切片的转录本(目标2)。这些变化如何改变外胚层中的转录水平和转录异构体，以及这随后如何影响潜在的间充质，将被详细研究。这些研究应该提供一个有价值的资源，详细说明外胚层和间充质在正常面部发育和颅面畸形中的动态相互作用。外胚层基因缺失的组织特异性是扰乱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是可用的，这些信号通路在外胚层放松调控时会发展成严重的颅面缺陷。这些模型将在目标3中进行研究，以探讨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.