Protein/Nucleic Acid Interaction & Vertebrate Embryology

蛋白质/核酸相互作用

• 批准号: 6811660
• 负责人: THOMAS D sargent
• 金额: --
• 依托单位: EUNICE KENNEDY SHRIVER NATIONAL INSTITUTE OF CHILD HEALTH & HUMAN DEVELOPMENT
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6811660
• 关键词: Xenopus; Xenopus oocyte; antisense nucleic acid; biological signal transduction; bone morphogenetic proteins; cadherins; developmental genetics; ectoderm; embryogenesis; gene interaction; homeobox genes; intermolecular interaction; microarray technology; neural crest; neural plate /tube; skin; transcription factor; vertebrate embryology

In vertebrates, the ectoderm is subdivided during gastrulation into four primary fates: epidermis and central nervous system (CNS) on the ventral and dorsal surfaces, respectively, and neural crest and sensory placodes located between these two domains. The goal of this project is to understand the mechanisms that determine how ectodermal cells choose between these pathways, and how the ensuing tissue patterning and differentiation are regulated. The experimental approach taken by this laboratory has been to use dependence upon cell-cell signaling as a criterion for identifying genes that may regulate the ectodermal developmental programs. Attention has been focused on four homeobox genes, Msx1, Dlx3, Dlx5 and Dlx6, and on the transcriptional activator AP-2alpha. We have found that the four homeobox genes are differentially regulated by a graded response to bone morphogenetic protein (BMP) signaling, resulting in different expression boundaries in vivo. We theorize that this can account for at least some of the major features of the spatial patterning of ectoderm during gastrulation. Msx1 appears to be involved in establishing the anterior boundary of the cement gland, a structure demarcating the most forward aspect of the neural plate, and in the induction of neural crest. Dlx3 seems to function in setting up the lateral boundary of neural crest. The roles of Dlx5 and Dlx6 may be related to establishing the boundary of the neural plate, and also in the formation of the sensory placodes. Neural crest induction in Xenopus requires two signals, a partially attenuated BMP signal and a Wnt/beta catenin signal. We have found that AP2alpha is responsible for conveying the BMP signal to the genome, and activation of a broad spectrum of neural crest-specific genes. AP2alpha is also imporant in the development of epidermis. We are using a hormone-inducible version of AP2alpha as a tool in conjunction with microarray analysis to identifiy target genes in both epidermis and neural crest. Several hundred such genes have now been identified, many of which have known functions such as transcription factors, signaling molecules, extracellular matrix-related enzymes and other structural or enzymatic functions. Many also have no known function, but are conserved in the mouse and human genomes and are thus likely to be important. We are now using antisense oligonucleotides and other strategies to study these functions, with the goal of learning how genes interact to control the formation and differentiation of epidermal and neural crest cells in the frog embryo. Since these tissues and genes are conserved throughout vertebrate phylogeny, our findings should have broad relevance to biomedical research and human health and development.

在脊椎动物中，外胚层在原肠胚形成期间被细分为四个主要命运：分别在腹侧和背侧表面上的表皮和中枢神经系统（CNS），以及位于这两个域之间的神经嵴和感觉基板。该项目的目标是了解决定外胚层细胞如何在这些途径之间进行选择的机制，以及如何调节随后的组织模式和分化。本实验室采取的实验方法是使用依赖于细胞-细胞信号传导作为鉴定可能调节外胚层发育程序的基因的标准。人们的注意力集中在四个同源异型盒基因，Msx 1，Dlx 3，Dlx 5和Dlx 6，以及转录激活因子AP-2 α上。我们已经发现，四个同源异型盒基因的差异调节骨形态发生蛋白（BMP）信号的分级响应，导致在体内不同的表达边界。我们推测，这可以解释原肠胚形成过程中外胚层空间模式的至少一些主要特征。msx 1似乎参与建立水泥腺的前边界，划分神经板的最向前的方面的结构，并在诱导神经嵴。Dlx 3可能在神经嵴外侧边界的建立中起作用。Dlx 5和Dlx 6的作用可能与神经板边界的建立和感觉基板的形成有关。 非洲爪蟾的神经嵴诱导需要两种信号，部分减弱的BMP信号和Wnt/β连环蛋白信号。我们已经发现，AP 2 α负责将BMP信号传递到基因组，并激活广泛的神经嵴特异性基因。AP 2 α在表皮的发育中也起重要作用。我们正在使用一种可诱导的AP 2 α作为工具，结合微阵列分析来鉴定表皮和神经嵴中的靶基因。现在已经鉴定了几百个这样的基因，其中许多具有已知的功能，例如转录因子、信号分子、细胞外基质相关酶和其他结构或酶功能。许多也没有已知的功能，但在小鼠和人类基因组中是保守的，因此可能是重要的。我们现在正在使用反义寡核苷酸和其他策略来研究这些功能，目的是了解基因如何相互作用以控制青蛙胚胎中表皮和神经嵴细胞的形成和分化。由于这些组织和基因在整个脊椎动物的发育过程中是保守的，我们的发现应该与生物医学研究和人类健康与发展具有广泛的相关性。