An Engineered Gene Network for Multicellular Pattern Formation

用于多细胞模式形成的工程基因网络

• 批准号: 7616783
• 负责人: Jeffrey Jay Tabor
• 金额: $ 5.01万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7616783
• 关键词: Adult; Affect; Binding; Biological; Biological Assay; Biology; Candidate Disease Gene; Cell Communication; Cell model; Cell surface; Cells; Communities; Computer Simulation; Defect; Development; Diffuse; Diffusion; Embryo; Engineered Gene; Engineering; Enzymes; Feedback; Fluorescence Microscopy; Gene Expression; Gene Expression Profile; Genes; Genetic; Genetic Engineering; Higher Order Chromatin Structure; Human Development; Kinetics; Knowledge; Lead; Life; Limb structure; Membrane; Modeling; Molecular; Monitor; Nucleic Acid Regulatory Sequences; Organ; Organism; Pattern; Pattern Formation; Population; Process; Production; Proteins; Radial; Reaction; Reporter Genes; Signal Transduction; Spottings; Synthetic Genes; System; Theoretical model; Time; Tissues; Travel; Validation; base; biological systems; cell growth; genetic activator; improved; in vivo; inhibitor/antagonist; intercellular communication; late disease onset; mathematical model; public health relevance; quorum sensing; transcription factor; two-dimensional

DESCRIPTION (provided by applicant): Highly differentiated multicellular organisms derive from morphologically symmetrical embryos with a single, discreet gene expression profile. This remarkable process is controlled by hierarchically organized networks of genetic regulatory elements which control the expression of the genes that drive morphological changes. These genetic networks frequently produce molecules which spread by diffusion or through cell surface signaling to regulate their own expression. Such systems enable multicellular patterning, the basis for the formation of higher order structures such as tissues and organs. Theoretical models have predicted that many patterns observed in biology can be generated by a genetic system composed of a short-ranging (local) self-activator and a long-ranging inhibitor. Intriguingly, the activator-inhibitor network is predicted to drive patterns of multicellular spots, stripes, oscillations and traveling waves under only slightly different kinetic parameters. Although many candidate gene networks have been proposed to use the activator- inhibitor strategy to regulate patterning, the complexity of biology has often precluded molecular-level validation. This proposal focuses on the construction of a synthetic, well-defined activator-inhibitor gene network capable of guiding pattern formation in populations of cells. The first step in this process is the construction of an autocatalytic component capable of guiding the radial propagation of a diffusible compound across a two-dimensional population of cells. This will be based on bacterial quorum sensing (cell-cell communication) systems. The autocatalytic propagation system will then be advanced to include an inhibitor component in order to dictate spot and stripe patterning within a community of growing cells. The inhibitor component selected will be based on an orthogonal quorum sensing system and will be freely membrane diffusible, enabling long range inhibition as compared to the less diffusible activator. The 'activated' state will be indicated by a fluorescent reporter gene and pattern formation will be monitored by time-lapse fluorescence microscopy under conditions compatible with cell growth. A computational reaction- diffusion model incorporating all engineered genetic components will be used to investigate the parameters affecting pattern formation. PUBLIC HEALTH RELEVANCE: During human development, groups of cells must function in concert to form the patterns which give rise to higher-order structures such as organs, and limbs. Errors in cellular pattern formation can result in a multitude of developmental defects as well as late onset diseases in adults. We aim to investigate the genetic mechanisms underlying these highly orchestrated pattern formation processes in an attempt to improve knowledge of natural and diseased cellular states.

描述(由申请人提供)：高度分化的多细胞生物来源于形态对称的胚胎，具有单一的、谨慎的基因表达谱。这一显着的过程是由遗传调控元件的分级组织网络控制的，这些网络控制着驱动形态变化的基因的表达。这些遗传网络经常产生分子，这些分子通过扩散或通过细胞表面信号来调节自己的表达。这样的系统使多细胞图案化成为可能，这是形成组织和器官等更高层次结构的基础。理论模型预测，生物学中观察到的许多模式可以由一个由短程(局部)自我激活剂和长程抑制物组成的遗传系统产生。有趣的是，据预测，激活剂-抑制物网络将在仅有微小不同的动力学参数下驱动多细胞斑点、条纹、振荡和行波的模式。尽管许多候选基因网络已被提出使用激活-抑制策略来调节模式，但生物学的复杂性往往排除了分子水平的验证。这项建议的重点是构建一个人工合成的、定义明确的激活剂-抑制物基因网络，能够指导细胞群体中的模式形成。这一过程的第一步是构建能够引导可扩散化合物在二维细胞群体中径向传播的自催化组件。这将基于细菌群体感应(细胞-细胞通讯)系统。然后，自动催化繁殖系统将被改进为包括抑制物组件，以便在生长中的细胞群落中指示斑点和条纹图案。所选的缓蚀剂成分将基于一个正交的群体感应系统，并且将是可自由膜扩散的，与扩散较少的激活剂相比，能够实现远距离的抑制。“激活”状态将由一个荧光报告基因指示，在与细胞生长相适应的条件下，将通过延时荧光显微镜监测模式的形成。一个包含所有工程遗传成分的计算反应-扩散模型将被用来研究影响模式形成的参数。与公共卫生相关：在人类发育过程中，细胞群必须协同工作，形成形成器官和肢体等更高层次结构的模式。细胞模式形成的错误可能会导致许多发育缺陷以及成人的迟发性疾病。我们的目标是研究这些高度协调的模式形成过程背后的遗传机制，试图改善对自然和疾病细胞状态的了解。