Protein/nucleic Acid Interactions In Vertebrate Embryoge

脊椎动物胚胎中蛋白质/核酸的相互作用

• 批准号: 7208216
• 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/7208216
• 关键词: Xenopus; bone morphogenetic proteins; cadherins; cell differentiation; cell migration; developmental genetics; ectoderm; embryogenesis; microarray technology; neural crest; nonmammalian vertebrate embryology; protooncogene; serine threonine protein kinase; transcription factor; yeast two hybrid system; zebrafish

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 among these pathways, and how the ensuing tissue patterning and differentiation are regulated, with a primary focus on the neural crest. Neural crest induction in Xenopus requires two signals, a partially attenuated BMP signal and a Wnt/beta catenin signal. We have found that the transcription factor TFAP2alpha is responsible for conveying the BMP signal to the genome, and activation of a broad spectrum of neural crest-specific genes. We used a hormone-inducible version of AP2alpha as a tool in conjunction with microarray analysis to identifiy target genes in both epidermis and neural crest. We are now focusing our research on determining the function of a small number of these genes. In particular, we are interested in two; one is a gene we named "Inca" (for Induced in Neural Crest by AP2). Inca is conserved in sequence and expression pattern in frogs, mice, and zebrafish. In the frog and zebrafish, we have used antisense oligonucleotides to show that Inca is required for proper development of the craniofacial cartilage and bones and other tissues where neural crest is involved. Yeast two-hybrid analysis has identified a p21-activated kinase, PAK4, as an interaction partner with Inca, supporting a model in which Inca functions to regulate cytoskeletal dynamics during neural crest cell migration and differentiation. Another gene encodes a novel protocadherin, PCNS, which is an adhesion molecule that is transiently expressed in neural crest and developing somites. Loss of PCNS results in failure of neural crest cell migration and also in abnormal somite and axial muscle development. Since these genes are conserved throughout vertebrate phylogeny, we expect our findings to broad relevance to biomedical research and human health and development.

在脊椎动物中，外胚层在原肠形成过程中被细分为四个主要命运：分别位于腹面和背面的表皮和中枢神经系统(CNS)，以及位于这两个区域之间的神经脊和感觉安慰剂。这个项目的目标是了解决定外胚层细胞如何在这些途径中选择的机制，以及随后的组织模式和分化是如何调节的，主要集中在神经脊。非洲爪哇神经隆起的诱导需要两个信号，一个是部分衰减的BMP信号，另一个是Wnt/β连接素信号。我们发现转录因子TFAP2Alpha负责将BMP信号传递到基因组，并激活广泛的神经峰特异性基因。我们使用激素诱导版本的AP2pha作为工具，结合微阵列分析来识别表皮和神经脊中的靶基因。我们现在的研究重点是确定这些基因中的一小部分的功能。特别是，我们对两个感兴趣；一个是我们命名为“Inca”的基因(AP2在神经峰中诱导的意思)。印加在青蛙、老鼠和斑马鱼中的序列和表达模式是保守的。在青蛙和斑马鱼中，我们使用了反义寡核苷酸来表明Inca是头面部软骨以及涉及神经脊的骨骼和其他组织正常发育所必需的。酵母双杂交分析发现，p21激活的蛋白激酶PAK4与INCA相互作用，支持INCA在神经峰细胞迁移和分化过程中调节细胞骨架动力学的模型。另一个基因编码一种新的原钙粘附素PCNS，它是一种黏附分子，在神经脊和发育中的体节中瞬时表达。PCNS的丢失会导致神经脊细胞迁移失败，也会导致体节和轴肌发育异常。由于这些基因在整个脊椎动物系统发育过程中都是保守的，我们预计我们的发现将与生物医学研究以及人类健康和发育广泛相关。