Mesodermal cell fate specification in C. elegans

秀丽隐杆线虫中胚层细胞命运规范

• 批准号: 8670756
• 负责人: Jun Liu
• 金额: $ 32.9万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-02 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8670756
• 关键词: Address; Area; Biology; Blast Cell Proliferation; Caenorhabditis elegans; Cell Cycle Regulation; Cell Differentiation process; Cell Nucleus; Cell Proliferation; Cell division; Cells; Chromatin; Clinical Research; Cyclin-Dependent Kinases; Development; Developmental Biology; Funding; Gene Expression; Gene Targeting; Genes; Germ Layers; Goals; Link; Logic; Mesoderm; Mesoderm Cell; Methods; Molecular Genetics; Multipotent Stem Cells; Muscle; Myoblasts; NuRD complex; Pattern; Process; Proliferating; Reagent; Resolution; Role; Signal Transduction; Smooth Muscle; Staging; Stem cells; Striated Muscles; Testing; Vertebrates; cell fate specification; cell type; human disease; in vivo; insight; novel; precursor cell; progenitor; programs; public health relevance; sex; stem cell biology; time orientation; tool; transcription factor

DESCRIPTION (provided by applicant): The mesodermal germ layer gives rise to a variety of functionally important cell types, including striated and non-striated muscles as well as non-muscle cells. Understanding the regulatory mechanisms underlying mesoderm diversification has widespread implications in basic biology, stem cell biology and clinical research. The C. elegans postembryonic mesodermal lineage, the M lineage, provides unique advantages for studying mesoderm diversification at single cell resolution. The M lineage is derived from a single pluripotent precursor cell, the M mesoblast, which during hermaphrodite postembryonic development proliferates and produces six cell types: striated bodywall muscles (BWM), non-muscle coelomocytes (CC), and four classes of non-striated sex muscles. Both M and its descendants divide in a reproducible pattern, which is under both developmental and cell cycle control. The M lineage is thus ideally suited to investigating how different mesodermal fates are diversified from a single progenitor cell, how positional information is integrated with lineage-intrinsic information, and how diverse programs of asymmetric patterning, cell division timing and orientation, and cell fate specification are integrated. Our long-term goal is to understand the regulatory logic of M lineage diversification in mechanistic detail. During the previous and current funding periods, we have successfully conducted in-depth molecular genetic studies on signaling and transcriptional regulatory mechanisms involved in M lineage development. Our results have allowed us to begin to assemble the regulatory networks involved in the proper specification of BWM, CC and the precursor of the non-striated muscles, the sex myoblast (SM). Our identification and characterization of several transcription factors involved in these fate specification processes have also provided key insights into how these factors may function in similar processes in vertebrates and how their malfunction may be linked to certain human diseases. More importantly, these studies have provided us with reagents and exciting opportunities to address additional fundamental questions in developmental biology. In this proposal, we will exploit the M lineage to dissect mechanisms involved in the specification and proliferation of multi-potent progenitors (Aim 1) and mechanisms underlying the specification of different types of non- striated/smooth muscles (Aim 2). Because many of the factors that we have identified are conserved in vertebrates and our studies of them in the M lineage have contributed to the mechanistic understanding of their functions in general, we propose to molecularly identify and characterize two "new" factors critical for M lineage development (Aim 3). Finally, we are at the point to exploit the M lineage to dissect the connection between cell type- and stage-specific chromatin features and transcription factor action during cell fate specification and cell differentiation in vivo, an important area in developmental biology that we know very little about. We propose to address this question using the newly developed INTACT (isolation of nuclei tagged in specific cell types) method (Aim 4).

描述（由申请人提供）：中胚层产生多种功能重要的细胞类型，包括横纹肌和非横纹肌以及非肌肉细胞。了解中胚层分化的调控机制在基础生物学、干细胞生物学和临床研究中具有广泛的意义。秀丽隐杆线虫胚胎后中胚层谱系，即M谱系，为在单细胞分辨率下研究中胚层分化提供了独特的优势。M系来源于一个单一的多能前体细胞，即M中母细胞，在雌雄同体的胚胎后发育过程中增殖并产生六种细胞类型：横纹肌（BWM）、非肌肉体腔细胞（CC）和四类非横纹肌性肌。M及其后代均以可繁殖的方式分裂，这是在发育和细胞周期控制下进行的。因此，M谱系非常适合研究不同的中胚层命运如何从单个祖细胞多样化，位置信息如何与谱系固有信息整合，以及不对称模式、细胞分裂时间和方向以及细胞命运规范的不同程序如何整合。我们的长期目标是了解M谱系多样化的机制细节的调控逻辑。在之前和当前的资助期内，我们成功地对M谱系发育中涉及的信号和转录调控机制进行了深入的分子遗传学研究。我们的结果使我们能够开始组装涉及BWM， CC和非横纹肌前体，性成肌细胞（SM）的适当规范的调节网络。我们对参与这些命运规范过程的几个转录因子的鉴定和表征也为这些因子如何在脊椎动物的类似过程中发挥作用以及它们的功能障碍如何与某些人类疾病相关联提供了关键见解。更重要的是，这些研究为我们提供了试剂和令人兴奋的机会来解决发育生物学中的其他基本问题。在本提案中，我们将利用M谱系来剖析多能祖细胞的特化和增殖机制（目的1）和不同类型的无纹/平滑肌的特化机制（目的2）。由于我们已经确定的许多因素在脊椎动物中是保守的，我们在M谱系中的研究有助于对其功能的机制理解，因此我们建议从分子上识别和表征两个对M谱系发育至关重要的“新”因素（Aim 3）。最后，我们将利用M谱系来剖析细胞命运规范和细胞分化过程中细胞类型和阶段特异性染色质特征与转录因子作用之间的联系，这是发育生物学中一个我们知之甚少的重要领域。我们建议使用新开发的integrity（分离特定细胞类型标记的细胞核）方法来解决这个问题（Aim 4）。