Dynamics of the SHR-SCR Network Controlling Asymmetric Cell Division

SHR-SCR 网络控制不对称细胞分裂的动力学

• 批准号: 8527289
• 负责人: Cara Winter
• 金额: $ 4.11万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-11-18 至 2015-11-17
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8527289
• 关键词: Arabidopsis; Behavior; Biology; Cell Lineage; Cell division; Cells; Complex; Computer Architectures; Data; Development; Equation; Event; Fluorescence; Foundations; Future; Genes; Genetic Research; Goals; Human; Image; Imaging Techniques; Individual; Kinetics; Knowledge; Laboratory Organism; Laser Scanning Confocal Microscopy; Life; Light; Link; Measures; Methods; Microscopy; Modeling; Organism; Output; Pattern; Plant Roots; Plants; Production; Property; Proteins; Public Health; Regulator Genes; Research; Solid; Spectrum Analysis; Study models; Techniques; Time; Tissues; Work; cell fate specification; daughter cell; human disease; insight; mathematical model; protein expression; public health relevance; research study; response; stem cells; stoichiometry; tool; transcription factor; two-photon

DESCRIPTION (provided by applicant): Understanding how gene regulatory networks (GRNs) orchestrate key developmental events such as tissue patterning, cell division and fate specification, is a major outstanding question in biology. GRNs are traditionally represented as static models comprised of edges and nodes. However, these models fail to capture the dynamic flow of information through the network that ultimately determines its developmental output. Mathematical modeling offers the potential for describing network dynamics. However, models require parameterization for which experimental data is often missing. Recent developments in the field of imaging have provided the tools to enable the observation of network dynamics in living organisms and the experimental determination of important parameters necessary for modeling their behavior. In Arabidopsis roots, a small network of genes regulated by the transcription factors SHORT-ROOT (SHR) and SCARECROW (SCR) controls the formative division of the immediate progeny of the ground tissue stem cells. These divisions are asymmetric, in that the daughter cells go on to produce distinct cell lineages, the cortex and endodermis. Over 20 years of genetic research have elucidated the topology of this network, yet little is known about how network components act together dynamically to effect cell division and fate specification. Here, I propose to use leading edge imaging techniques to experimentally determine important kinetic parameters of the SHR-SCR network and use these to model its function. Specifically, I will use two-photon light sheet microscopy to measure in real-time the timing and levels of changes in protein expression of network components as cells divide in wild-type plants and in response to SHR induction (Aim 1). I will then determine the specific SHR-SCR complexes formed in their cellular context both before and after cell division using a new technique from the field of correlation spectroscopy called Number and Brightness (Aim 2). And finally, I will use these experimentally determined parameters and interactions to model the behavior of the SHR-SCR network (Aim 3). This work will shed light on how this network dynamically controls cell division and the specification of cell fate in the Arabidopsis root. It will also explore new methods for understanding gene network function that may be generally applicable to all organisms.

描述（由申请人提供）：了解基因调控网络（GRN）如何协调组织模式、细胞分裂和命运规范等关键发育事件，是生物学中的一个主要悬而未决的问题。 GRN 传统上表示为由边和节点组成的静态模型。然而，这些模型无法捕获网络中最终决定其发展输出的动态信息流。数学建模提供了描述网络动态的潜力。然而，模型需要参数化，而实验数据往往缺失。成像领域的最新发展提供了工具，使人们能够观察生物体中的网络动态，并通过实验确定对其行为进行建模所需的重要参数。在拟南芥根中，由转录因子 SHORT-ROOT (SHR) 和 SCARECROW (SCR) 调节的小型基因网络控制着地面组织干细胞直系后代的形成分裂。这些分裂是不对称的，因为子细胞继续产生不同的细胞谱系：皮质和内皮层。 20 多年的基因研究已经阐明了该网络的拓扑结构，但对于网络组件如何动态地协同作用以影响细胞分裂和命运规范却知之甚少。在这里，我建议使用前沿成像技术通过实验确定 SHR-SCR 网络的重要动力学参数，并使用这些参数对其功能进行建模。具体来说，我将使用双光子光片显微镜实时测量野生型植物中细胞分裂时网络成分蛋白质表达变化的时间和水平以及对 SHR 诱导的反应（目标 1）。然后，我将使用相关光谱学领域称为“数量和亮度”（目标 2）的新技术来确定细胞分裂前后在细胞环境中形成的特定 SHR-SCR 复合物。最后，我将使用这些通过实验确定的参数和交互来对 SHR-SCR 网络的行为进行建模（目标 3）。这项工作将揭示该网络如何动态控制拟南芥根中的细胞分裂和细胞命运的规范。它还将探索了解基因网络功能的新方法，这些方法可能普遍适用于所有生物体。