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(申请人提供)：了解基因调控网络(GRN)如何协调关键的发育事件，如组织模式、细胞分裂和命运指定，是生物学中的一个主要悬而未决的问题。GRN传统上被表示为由边和节点组成的静态模型。然而，这些模型未能捕捉到信息通过网络的动态流动，而这最终决定了网络的发展产出。数学建模为描述网络动态提供了可能性。然而，模型需要参数化，而实验数据往往是缺失的。成像领域的最新发展为观察生物体中的网络动力学和通过实验确定模拟其行为所需的重要参数提供了工具。在拟南芥的根中，由转录因子短根(SHR)和稻草人(SCR)调控的一个小的基因网络控制着基本组织干细胞直接后代的形成分裂。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，即皮质和内胚层。20多年的遗传学研究已经阐明了这个网络的拓扑结构，但对于网络组件如何动态地共同作用来影响细胞分裂和命运指定，人们知之甚少。在这里，我建议使用前沿成像技术来实验确定SHR-SCR网络的重要动力学参数，并使用这些参数来模拟其功能。具体地说，我将使用双光子光片显微镜实时测量野生型植物细胞分裂时网络组件蛋白质表达的时间和水平的变化，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的一种名为数量和亮度的新技术(目标2)来确定在细胞分裂前后的细胞上下文中形成的特定的SHR-SCR复合体。最后，我将使用这些实验确定的参数和交互作用来模拟SHR-SCR网络的行为(目标3)。这项工作将阐明这个网络如何动态地控制拟南芥根中细胞分裂和细胞命运的指定。它还将探索理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。