ROLE OF TFII-I IN CRANIOFACIAL DEVELOPMENT

描述（申请人提供）：颅面相关出生缺陷占所有先天性异常的1/3。神经嵴细胞（NCC）缺陷是这些疾病的主要原因；然而，参与颅面形态发生的信号通路尚不清楚。因此，了解神经嵴发育的分子机制是了解人类颅面疾病的必要条件。我们的长期目标是确定指导NCC形态发生的调控途径。本应用程序的目的是确定TFII-I转录因子在颅面发育中的分子和遗传作用。编码这种蛋白质的Gtf2i等位基因的缺失会导致小鼠颅面缺陷。TFII-I通过与组蛋白去乙酰化酶和Smad2的相互作用调节靶基因的转录，并在神经嵴源性组织中表达。我们假设TFII-I的作用之一是控制对神经嵴形态发生至关重要的信号级联。因此，我们建议对Gtf2i进行深入分析，以了解其在神经嵴发育中的作用。首先，将分析突变胚胎中颅面缺陷的分子和细胞变化。其次，我们将利用微阵列和染色质免疫沉淀分析来鉴定一组由TFII-I调控的下游靶基因。第三，Gtf2i等位基因将通过条件Cre/LoxP重组系统在NCC谱系中被废除。本研究的结果将使我们能够确定参与神经嵴衍生结构形态发生的tfii - 1依赖基因和信号通路。这些研究将有助于更好地了解人类出生缺陷的颅面遗传途径和发病机制。

DESCRIPTION (provided by applicant): Craniofacial related birth defects account for 1/3rd of all congenital anomalies. Defects in neural crest cells (NCC) cause most of these disorders; however, the signaling pathways involved in craniofacial morphogenesis are poorly understood. Therefore, knowledge of the molecular mechanisms of neural crest development is necessary to understand human craniofacial disorders. Our long-term goal is to identify the regulatory pathways that instruct NCC morphogenesis. The objective of this application is to determine the molecular and genetic role of the TFII-I transcription factor in craniofacial development. Deletion of the Gtf2i allele, which encodes this protein causes craniofacial defects in mice. TFII-I regulates the transcription of target genes via interactions with histone deacetylases and Smad2 and is expressed in neural crest-derived tissues. We hypothesize that 1 of the roles of TFII-I is to control signaling cascades critical for neural crest morphogenesis. We, therefore, propose an in depth analysis of Gtf2i to understand its role during neural crest development. First, molecular and cellular changes underlying craniofacial defects will be analyzed in mutant embryos. Second, a set of downstream target genes regulated by TFII-I in cranial NCC will be identified using microarray and chromatin immunoprecipitation analysis. Third, the Gtf2i allele will be abrogated in the NCC lineage with the conditional Cre/LoxP recombination system. The outcome of the proposed research will allow us to identify the TFII-l-dependent genes and signaling pathways involved in the morphogenesis of neural crest-derived structures. These studies will provide a better understanding of craniofacial genetic pathways and pathogenesis of human birth defects.