Cellular and Genetic Regulation of Heart Tube Assembly in Zebrafish

斑马鱼心管组装的细胞和遗传调控

• 批准号: 7688518
• 负责人: JENNIFER Schumacher
• 金额: $ 1.8万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7688518
• 关键词: Address; Automobile Driving; Behavior; Bilateral; Biological Models; Blood Vessels; Cadherins; Cardiac; Cardiac Myocytes; Cell Adhesion; Cell Polarity; Cells; Congenital Heart Defects; DNA Sequence Rearrangement; Data; Embryo; Endocardium; Failure; Genes; Genetic; Genetic Screening; Goals; Heart; Image; Immigration; Individual; Intercellular Junctions; Knowledge; Maintenance; Microscopy; Molecular; Morphogenesis; Morphology; Movement; Myocardial; Myocardium; Organ; Pathway interactions; Pattern; Play; Population; Positioning Attribute; Process; Regulation; Reporter; Research; Resolution; Retinal Cone; Role; Screening procedure; Shapes; Signal Transduction; System; Testing; Time; Transgenes; Transgenic Organisms; Tube; Work; Zebrafish; base; cadherin 5; cell behavior; cell motility; cell type; chemical genetics; gain of function; gastrulation; gene function; heart visualization; intercalation; interest; loss of function; migration; precursor cell; research study; time use

DESCRIPTION (provided by applicant): Constructing an organ is an elaborate process that is not well understood. What mechanisms drive cells to attain the appropriate position and shape within an organ? How do different cell types within an organ interact during morphogenesis? These questions can be addressed in the context of the heart, which undergoes elaborate morphogenesis to rearrange bilateral populations of myocardial and endocardial precursor cells into a highly specialized multi-chambered organ. Heart shape relies on proper cell movements during early morphogenesis, when both cell types organize to form a two-layered heart tube consisting of an outer myocardium and an inner endocardium. Thus it is of interest to elucidate the mechanisms underlying the process of heart tube formation. This is particularly pertinent to understanding the causes of congenital heart defects, many of which are a result of failure to arrange cardiac cells properly during early heart morphogenesis. The goal of my postdoctoral research is to take advantage of the zebrafish as a model system to elucidate key components of the cellular and genetic regulation responsible for heart tube assembly. The zebrafish is an ideal system in which to study cardiac cell movements due to the easy visualization of the heart, the availability of transgenes appropriate for high-resolution time-lapse imaging, and the options for manipulating gene function through loss- and gain-of-function approaches. Previous work in the Yelon lab has discovered some of the fundamental cellular behaviors and genes required for myocardial precursor migration towards the midline. Following migration, cardiomyocytes coalesce around the endocardium to form a shallow cone, which then extends to form the linear heart tube. Little is known about the cellular and molecular mechanisms driving heart tube extension. Based on my preliminary studies, I hypothesize that myocardial cells undergo mediolateral intercalations to drive extension, and that the planar cell polarity pathway plays a role in orchestrating myocardial tube extension. The regulation of endocardial tube extension may be quite different, as endothelial tube assembly relies on precise control of cell-cell contacts. My preliminary data suggest that, during endocardial morphogenesis, cells begin directional migration as individuals followed by formation of cell-cell junctions, and that VEcadherin plays a role in this process. I will test these hypotheses through the following specific aims: 1) Determining the cell behaviors driving myocardial and endocardial tube extension, 2) Determining the role of planar cell polarity in myocardial tube extension and the role of VE-cadherin in endocardial tube extension, and 3) Conducting a chemical genetic screen to identify new regulators of heart tube extension.

描述（由申请人提供）：构建器官是一个复杂的过程，还没有很好地理解。是什么机制驱动细胞在器官中获得适当的位置和形状？器官内不同类型的细胞在形态发生过程中如何相互作用？这些问题可以在心脏的背景下得到解决，心脏经历了精心的形态发生，将心肌和内皮细胞前体细胞的双边群体重新排列成一个高度专业化的多腔器官。心脏的形状依赖于早期形态发生过程中细胞的适当运动，此时两种细胞类型组织形成由外层心肌和内层内膜组成的双层心管。因此，阐明心管形成过程的机制是有意义的。这对于理解先天性心脏缺陷的原因特别相关，其中许多是在早期心脏形态发生期间未能正确排列心脏细胞的结果。我的博士后研究的目标是利用斑马鱼作为模型系统来阐明负责心管组装的细胞和遗传调控的关键组成部分。斑马鱼是研究心脏细胞运动的理想系统，因为它易于可视化心脏，适用于高分辨率延时成像的转基因的可用性，以及通过功能丧失和获得方法操纵基因功能的选择。Yelon实验室以前的工作已经发现了心肌前体向中线迁移所需的一些基本细胞行为和基因。迁移后，心肌细胞在内皮细胞周围合并形成浅圆锥，然后延伸形成线性心管。关于驱动心管延伸的细胞和分子机制知之甚少。基于我的初步研究，我假设，心肌细胞进行中外侧插入驱动扩展，平面细胞极性通路在编排心肌管延伸中发挥作用。内皮管延伸的调节可能是完全不同的，因为内皮管组装依赖于细胞-细胞接触的精确控制。我的初步数据表明，在内皮细胞形态发生过程中，细胞开始定向迁移，随后形成细胞-细胞连接，而VE钙粘蛋白在这一过程中发挥作用。我将通过以下具体目标来测试这些假设：1）确定驱动心肌和内膜管延伸的细胞行为，2）确定平面细胞极性在心肌管延伸中的作用和VE-钙粘蛋白在内膜管延伸中的作用，以及3）进行化学遗传筛选以鉴定心管延伸的新调节剂。