Genetic regulation of cardiac patterning in zebrafish

斑马鱼心脏模式的遗传调控

• 批准号: 6422384
• 负责人: DEBORAH YELON
• 金额: $ 31.97万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-01 至 2006-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6422384
• 关键词: atrium; developmental genetics; early embryonic stage; gene mutation; heart function; heart ventricle; histogenesis; myocardium; nonmammalian vertebrate embryology; retinaldehyde; transcription factor; transfection; zebrafish

The embryonic vertebrate heart has a simple anterior- posterior pattern: it is divided into two major chambers, an anterior ventricle and a posterior atrium. These two chambers are morphologically distinct; furthermore, the ventricular myocardium differs from the atrial myocardium by many molecular, histological, and physiological criteria. These intrinsic differences between the ventricle and the atrium are critical for proper cardiac function, and neonatal and adult cardiac conditions are often associated with chamber formation defects. Despite the functional importance of proper cardiac patterning, its genetic regulation is not yet understood. Through studies of cardiac chamber formation in the zebrafish embryo, we are identifying the genes that specify ventricular and atrial cell fates. In this proposal, we use zebrafish mutations to determine the roles of three key players in cardiac patterning: the transcription factor Hand2, the retinoic acid-synthesizing enzyme retinaldehyde dehydrogenase 2 (Raldh2), and an unidentified gene (heart of darkness (hod)). First, by creating fate maps for ventricular and atrial progenitors in wild-type and hand2 mutant zebrafish embryos, we will test models regarding the cellular function of Hand2 during myocardial differentiation and ventricle formation. Second, studies of raldh2 mutant embryos, including phenotypic characterization, fate mapping, and mosaic analysis, will test the hypothesis that retinoic acid signaling regulates atrial specification. Third, similar molecular and cellular analyses of the hod mutant phenotype will test the hypothesis that hod, like hand2, regulates early steps of myocardial differentiation and ventricle formation. Finally, we will clone the hod gene and begin the analysis of the hod gene product. Altogether, these experiments will provide a foundation for understanding the genetic pathways that regulate cardiac patterning in vertebrates.

胚胎脊椎动物的心脏有一个简单的前后模式：它分为两个主要的腔室，一个前室和一个后心房。这两个腔室在形态上是不同的；此外，心室心肌在许多分子、组织学和生理标准上与心房心肌不同。心室和心房之间的这些内在差异对正常的心功能至关重要，新生儿和成人的心脏疾病通常与心室形成缺陷有关。尽管正确的心脏模式具有重要的功能，但其遗传调控尚不清楚。通过对斑马鱼胚胎心脏腔形成的研究，我们正在确定指定心室和心房细胞命运的基因。在这项研究中，我们利用斑马鱼的突变来确定三个关键因素在心脏模式中的作用：转录因子Hand2、视黄酸合成酶视黄醛脱氢酶2 （Raldh2）和一个未知基因（黑暗之心（hod））。首先，通过在野生型和hand2突变斑马鱼胚胎中创建心室和心房祖细胞的命运图谱，我们将测试hand2在心肌分化和心室形成过程中的细胞功能模型。其次，对raldh2突变胚胎的研究，包括表型表征、命运定位和马赛克分析，将验证视黄酸信号调节心房规范的假设。第三，对hod突变表型的类似分子和细胞分析将验证hod和hand2一样调节心肌分化和心室形成的早期步骤的假设。最后，我们将克隆hod基因，并开始对hod基因产物进行分析。总之，这些实验将为理解调节脊椎动物心脏模式的遗传途径提供基础。