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: 6664175
• 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/6664175
• 关键词: Xenopus oocyte; animal genetic material tag; bone morphogenetic proteins; cadherins; cell adhesion molecules; developmental genetics; ectoderm; embryogenesis; genetically modified animals; intermolecular interaction; laboratory mouse; messenger RNA; neural crest; nucleic acid sequence; protein tyrosine kinase; skin; transcription factor; vertebrate embryology; zebrafish

In vertebrates, as in other animals, the ectoderm has two primary fates, epidermis and central nervous system (CNS). The goal of this project is to understand the mechanisms that determine how ectodermal cells choose between these two pathways, and how the ensuing tissue patterning and differentiation are regulated. It has been well established that signaling by bone morphogenetic proteins (BMPs) is the primary event that initiates epidermal development in the amphibian embryo. The experimental approach taken by this laboratory has been to use dependence upon such signaling as a criterion for identifying genes that may regulate the epidermal/neural developmental program. Attention has been focused on the Distal-less homologs Dlx3, 5 and 6 and on the transcriptional activator AP-2. Additional genes are being sought using subtractive hybridization/microarray techniques. We have found that the three Dlx genes are differentially regulated by a graded response to BMP signaling, and that this can account for at least some of the major features of the spatial pattern of Dlx gene expression in the gastrula. Dlx3 appears to be involved in establishing the lateral boundary of cranial neural crest induction, in a manner similar to the anti-neural properties we previously discovered for this gene. Interestingly, this inhibitory function does not appear to involve direct regulation of transcription by Dlx3, but is more likely dependent upon protein-protein interactions. The roles of Dlx5 and Dlx6 remain obscure, but the possibility that this subfamily of homeobox genes function to interpret a morphogenetic gradient in the embryo is very intriguing. The findings that AP2 expression is BMP-dependent, and that over-expression of this factor can rescue epidermal gene activity in BMP-disabled ectoderm are also highly interesting, as this gene was identified by our laboratory several years ago as a potential epidermal regulatory factor, using a promoter analysis approach. We have also found that AP2 plays an important role in the development of neural crest cells, and are now examining the interactions between AP2, Dlx3 and other factors at the protein-protein level, and using microarry analyis to search for target genes regulated by these factors.

与其他动物一样，脊椎动物的外胚层有两个主要命运：表皮和中枢神经系统（CNS）。该项目的目标是了解决定外胚层细胞如何在这两种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。众所周知，骨形态发生蛋白 (BMP) 发出的信号是两栖动物胚胎中启动表皮发育的主要事件。该实验室采取的实验方法是利用对此类信号传导的依赖性作为识别可能调节表皮/神经发育程序的基因的标准。人们的注意力集中在 Distal-less 同源物 Dlx3、5 和 6 以及转录激活剂 AP-2 上。正在使用消减杂交/微阵列技术寻找其他基因。我们发现，三个 Dlx 基因受到对 BMP 信号传导的分级反应的差异调节，这至少可以解释原肠胚中 Dlx 基因表达空间模式的一些主要特征。 Dlx3 似乎参与建立颅神经嵴诱导的侧向边界，其方式类似于我们之前发现的该基因的抗神经特性。有趣的是，这种抑制功能似乎并不涉及 Dlx3 对转录的直接调节，而更可能依赖于蛋白质-蛋白质相互作用。 Dlx5 和 Dlx6 的作用仍然不清楚，但这个同源框基因亚家族解释胚胎形态发生梯度的可能性非常有趣。 AP2 表达依赖于 BMP，并且该因子的过度表达可以挽救 BMP 禁用的外胚层中的表皮基因活性，这一发现也非常有趣，因为我们的实验室几年前使用启动子分析方法将该基因鉴定为潜在的表皮调节因子。我们还发现AP2在神经嵴细胞的发育中发挥着重要作用，目前正在蛋白质-蛋白质水平上研究AP2、Dlx3和其他因子之间的相互作用，并利用微阵列分析来寻找这些因子调控的靶基因。