Genetic Analysis of Pathways Controlling Nephron Segmentation Using the Zebrafish

描述(由申请人提供)： 肾前体细胞生物学为预防和治疗先天性肾缺陷提供了宝贵的见解，先天性肾缺陷是儿童慢性肾功能衰竭的主要原因之一。通过对小鼠的基因打靶研究，人们对触发肾脏形成的初始阶段的事件有了很多了解。然而，由于哺乳动物肾脏发育的复杂性，对于肾脏前体如何形成成熟的肾单位--肾脏的基本单位，由一系列离散的功能片段组成--缺乏了解。斑马鱼模型系统提供了一个独特的机会来发现肾单位是如何分割的。斑马鱼胚胎形成了一个解剖上简单的肾脏，只有两个肾单位，最近被证明拥有类似哺乳动物的节段组织。斑马鱼模型由于胚胎的体外受精和透明，结合该系统中现有的强大的分子工具，对于研究肾祖细胞的功能丧失和功能获得是有利的。我们建议进一步研究维甲酸(RA)缺失突变体灯泡中肾单位节段的变化，并确定肾前体细胞在肾脏形成的早期阶段对RA信号作出反应的机制。此外，我们还将分配Irx3b和Evi1转录因子在随后的片段形成事件中的角色和相互关系。这个K01应用程序的总体目标是利用斑马鱼模型的优势，通过建立负责肾脏前体指定的路径的层次结构来描述引导肾单位成熟的遗传路径。这一奖项将为候选人丽贝卡·温格特博士提供一段时间的指导研究培训，在艾伦·戴维森博士的实验室里进行，艾伦·戴维森博士是一位经验丰富的斑马鱼生物学家，也是肾病学的新兴领导者。这项培训对温格特博士培养技能至关重要，以实现她的目标，即成为一名成功的独立研究员，在一个致力于研究肾脏祖细胞发育计划的研究小组中，并将这一认识应用于人类肾脏出生缺陷的起源和预防/治疗。 公共卫生相关性：了解肾脏如何发育对于了解人类肾脏先天缺陷至关重要，先天缺陷通常会导致肾衰竭。这项拟议的研究将确定肾脏的功能单位肾单位在发育过程中是如何正确形成的。对这一过程的理解有可能指导肾脏畸形的治疗方法的产生和预防肾脏疾病。

DESCRIPTION (provided by applicant): Renal progenitor biology proffers valuable insight into the prevention and treatment of congenital kidney defects, which are among the leading causes of chronic renal failure in children. Much is known about the events that trigger the initial stages of kidney formation from gene targeting studies in mice. However, due to the complex nature of mammalian kidney development, there is a paucity of knowledge regarding how renal progenitors form mature nephrons-the fundamental units of the kidney that are made up of a series of discrete functional segments. The zebrafish model system provides a unique opportunity to discover how nephron segmentation occurs. Zebrafish embryos form an anatomically simple kidney of just two nephrons, which were recently shown to possess a segment organization akin to mammals. The zebrafish model is advantageous for loss- and gain-of-function genetic studies in renal progenitors due to the external fertilization and transparency of embryos, combined with the powerful molecular tools now available in this system. We propose to further characterize the nephron segment alterations in the retinoic acid (RA) deficient mutant, light bulb, and to determine the mechanisms by which renal progenitors respond to RA signaling during early stages of nephrogenesis. In addition, we will assign the roles and interrelationships between the Irx3b and Evi1 transcription factors in subsequent events of segment formation. The overall goal of this K01 application is to use the advantages of the zebrafish model to delineate the genetic pathways that direct nephron maturation by building a hierarchy of the pathways responsible for renal progenitor specification. This award will provide the candidate, Dr. Rebecca Wingert, a period of mentored research training in the laboratory of Dr. Alan Davidson, an experienced zebrafish biologist and emerging leader in nephrology. This training is essential for Dr. Wingert to develop the repertoire of skills to achieve her goal of becoming a successful, independent investigator with a research group dedicated to studying the developmental programs of renal progenitors and the application of this understanding to the origins and prevention/treatment of renal birth defects in humans. PUBLIC HEALTH RELEVANCE: Knowledge of how the kidney develops is paramount to understanding kidney birth defects in humans, which commonly lead to kidney failure. The proposed research will determine how nephrons, the functional unit of the kidney, are properly formed during development. The understanding of this process has the potential to guide generation of therapies for kidney malformations and to prevent kidney disease.